MIT News - Space, astronomy and planetary science - NASA - Kavli Institute - Exoplanets - space - Astronomyhttps://news.mit.edu/rss/topic/space
MIT News is dedicated to communicating to the media and the public the news and achievements of the students, faculty, staff and the greater MIT community.enSun, 18 Mar 2018 23:59:59 -0400Scientists detect radio echoes of a black hole feeding on a starhttps://news.mit.edu/2018/scientists-detect-radio-echoes-black-hole-feeding-star-0319
Signals suggest black hole emits a jet of energy proportional to the stellar material it gobbles up.Sun, 18 Mar 2018 23:59:59 -0400Jennifer Chu | MIT News Officehttps://news.mit.edu/2018/scientists-detect-radio-echoes-black-hole-feeding-star-0319<p>On Nov. 11, 2014, a global network of telescopes picked up signals from 300 million light years away that were created by a tidal disruption flare — an explosion of electromagnetic energy that occurs when a black hole rips apart a passing star. Since this discovery, astronomers have trained other telescopes on this very rare event to learn more about how black holes devour matter and regulate the growth of galaxies.</p>
<p>Scientists from MIT and Johns Hopkins University have now detected radio signals from the event that match very closely with X-ray emissions produced from the same flare 13 days earlier. They believe these radio “echoes,” which are more than 90 percent similar to the event’s X-ray emissions, are more than a passing coincidence. Instead, they appear to be evidence of a giant jet of highly energetic particles streaming out from the black hole as stellar material is falling in.</p>
<p>Dheeraj Pasham, a postdoc in MIT’s Kavli Institute for Astrophysics and Space Research, says the highly similar patterns suggest that the power of the jet shooting out from the black hole is somehow controlled by the rate at which the black hole is feeding on the obliterated star.</p>
<p>“This is telling us the black hole feeding rate is controlling the strength of the jet it produces,” Pasham says. “A well-fed black hole produces a strong jet, while a malnourished black hole produces a weak jet or no jet at all. This is the first time we’ve seen a jet that’s controlled by a feeding supermassive black hole.”</p>
<p>Pasham says scientists have suspected that black hole jets are powered by their accretion rate, but they have never been able to observe this relationship from a single event.</p>
<p>“You can do this only with these special events where the black hole is just sitting there doing nothing, and then suddenly along comes a star, giving it a lot of fuel to power itself,” Pasham says. “That’s the perfect opportunity to study such things from scratch, essentially.”</p>
<p>Pasham and his collaborator, Sjoert van Velzen of Johns Hopkins University, report their results in a paper published this week in the <em>Astrophysical Journal.</em></p>
<p><strong>Up for debate</strong></p>
<p>Based on theoretical models of black hole evolution, combined with observations of distant galaxies, scientists have a general understanding for what transpires during a tidal disruption event: As a star passes close to a black hole, the black hole’s gravitational pull generates tidal forces on the star, similar to the way in which the moon stirs up tides on Earth.</p>
<p>However, a black hole’s gravitational forces are so immense that they can disrupt the star, stretching and flattening it like a pancake and eventually shredding the star to pieces. In the aftermath, a shower of stellar debris rains down and gets caught up in an accretion disk — a swirl of cosmic material that eventually funnels into and feeds the black hole.</p>
<p>This entire process generates colossal bursts of energy across the electromagnetic spectrum. Scientists have observed these bursts in the optical, ultraviolet, and X-ray bands, and also occasionally in the radio end of the spectrum. The source of the X-ray emissions is thought to be ultrahot material in the innermost regions of the accretion disk, which is just about to fall into the black hole. Optical and ultraviolet emissions likely arise from material further out in the disk, which will eventually be pulled into the black hole.</p>
<p>However, what gives rise to radio emissions during a tidal disruption flare has been up for debate.</p>
<p>“We know that the radio waves are coming from really energetic electrons that are moving in a magnetic field — that is a well-established process,” Pasham says. “The debate has been, where are these really energetic electrons coming from?”</p>
<p>Some scientists propose that, in the moments after the stellar explosion, a shockwave propagates outward and energizes the plasma particles in the surrounding medium, in a process that in turn emits radio waves. In such a scenario, the pattern of emitted radio waves would look radically different from the pattern of X-rays produced from infalling stellar debris.</p>
<p>“What we found basically challenges this paradigm,” Pasham says.</p>
<p><strong>A shifting pattern</strong></p>
<p>Pasham and van Velzen looked through data recorded from a tidal disruption flare discovered in 2014 by the global telescope network ASASSN (All-sky Automated Survey for Supernovae). Soon after the initial discovery, multiple electromagnetic telescopes focused on the event, which astronomers coined ASASSN-14li. Pasham and van Velzen perused radio data from three telescopes of the event over 180 days.</p>
<p>The researchers looked through the compiled radio data and discovered a clear resemblance to patterns they had previously observed in X-ray data from the same event. When they fit the radio data over the X-ray data, and shifted the two around to compare their similarities, they found the datasets were most similar, with a 90 percent resemblance, when shifted by 13 days. That is, the same fluctuations in the X-ray spectrum appeared 13 days later in the radio band.</p>
<p>“The only way that coupling can happen is if there is a physical process that is somehow connecting the X-ray-producing accretion flow with the radio-producing region,” Pasham says.</p>
<p>From this same data, Pasham and van Velzen calculated the size of the X-ray-emitting region to be about 25 times the size of the sun, while the radio-emitting region was about 400,000 times the solar radius.</p>
<p>“It’s not a coincidence that this is happening,” Pasham says. “Clearly there’s a causal connection between this small region producing X-rays, and this big region producing radio waves.”</p>
<p>The team proposes that the radio waves were produced by a jet of high-energy particles that began to stream out from the black hole shortly after the black hole began absorbing material from the exploded star. Because the region of the jet where these radio waves first formed was incredibly dense (tightly packed with electrons), a majority of the radio waves were immediately absorbed by other electrons.</p>
<p>It was only when electrons traveled downstream of the jet&nbsp;that the radio waves could escape — producing the signal that the researchers eventually detected. Thus, they say, the strength of the jet must be controlled by the accretion rate, or the speed at which the black hole is consuming X-ray-emitting stellar debris.</p>
<p>Ultimately, the results may help scientists better characterize the physics of jet behavior — an essential ingredient in modeling the evolution of galaxies. It’s thought that galaxies grow by producing new stars, a process that requires very cold temperatures. When a black hole emits a jet of particles, it essentially heats up the surrounding galaxy, putting a temporary stop on stellar production. Pasham says the team’s new insights into jet production and black hole accretion may help to simplify models of galaxy evolution.</p>
<p>“If the rate at which the black hole is feeding is proportional to the rate at which it’s pumping out energy, and if that really works for every black hole, it’s a simple prescription you can use in simulations of galaxy evolution,” Pasham says. “So this is hinting toward some bigger picture.”</p>
Artist's impression of an inner accretion flow and a jet from a supermassive black hole when it is actively feeding, for example, from a star that it recent tore apart.Image: ESO/L. CalçadaAstronomy, Astrophysics, Black holes, Kavli Institute, Physics, Research, School of Science, Space, astronomy and planetary scienceAstronomers detect earliest evidence yet of hydrogen in the universehttps://news.mit.edu/2018/astronomers-detect-earliest-evidence-yet-hydrogen-universe-0228
Emitted just 180 million years after Big Bang, signal indicates universe was much colder than expected.Wed, 28 Feb 2018 12:59:59 -0500Jennifer Chu | MIT News Officehttps://news.mit.edu/2018/astronomers-detect-earliest-evidence-yet-hydrogen-universe-0228<p>In a study published today in the journal <em>Nature</em>, astronomers from MIT and Arizona State University report that a table-sized radio antenna in a remote region of western Australia has picked up faint signals of hydrogen gas from the primordial universe.</p>
<p>The scientists have traced the signals to just 180 million years after the Big Bang, making the detection the earliest evidence of hydrogen yet observed.</p>
<p>They also determined that the gas was in a state that would have been possible only in the presence of the very first stars. These stars, blinking on for the first time in a universe that was previously devoid of light, emitted ultraviolet radiation that interacted with the surrounding hydrogen gas. As a result, hydrogen atoms across the universe began to absorb background radiation — a pivotal change that the scientists were able to detect in the form of radio waves.</p>
<p>The findings provide evidence that the first stars may have started turning on around 180 million years after the Big Bang.</p>
<p>“This is the first real signal that stars are starting to form, and starting to affect the medium around them,” says study co-author Alan Rogers, a scientist at MIT’s Haystack Observatory. “What’s happening in this period is that some of the radiation from the very first stars is starting to allow hydrogen to be seen. It’s causing hydrogen to start absorbing the background radiation, so you start seeing it in silhouette, at particular radio frequencies.”</p>
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<p>Certain characteristics in the detected radio waves also suggest that hydrogen gas, and the universe as a whole, must have been twice as cold as scientists previously estimated, with a temperature of about 3 kelvins, or –454 degrees Fahrenheit. Rogers and his colleagues are unsure precisely why the early universe was so much colder, but some researchers have suggested that interactions with dark matter may have played some role.</p>
<p>“These results require some changes in our current understanding of the early evolution of the universe,” says Colin Lonsdale, director of Haystack Observatory. “It would affect cosmological models and require theorists to put their thinking caps back on to figure out how that would happen.”</p>
<p>Rogers’ co-authors are lead author Judd Bowman of Arizona State University (ASU), along with Thomas Mozdzen, Nivedita Mahesh, and Raul Monsalve, from the University of Colorado.</p>
<p><strong>Turning on, tuning in</strong></p>
<p>The scientists detected the primordial hydrogen gas using EDGES (Experiment to Detect Global EoR Signature), a small ground-based radio antenna located in western Australia, and funded by the National Science Foundation.</p>
<p>The antennas and portions of the receiver were designed and constructed by Rogers and the Haystack Observatory team; Bowman, Monsalve, and the ASU team added an automated antenna reflection measurement system to the receiver, outfitted a control hut with the electronics, constructed the ground plane, and conducted the field work for the project. Australia’s Commonwealth Scientific and Industrial Research Organization provided on-site infrastructure for the EDGES project.</p>
<p>The current version of EDGES is the result of years of design iteration and instrument calibration in order to reach the levels of precision necessary for successfully achieving an extremely difficult measurement.</p>
<p>The instrument was originally designed to pick up radio waves emitted from a time in the universe’s history known as the Epoch of Reionization, or EoR. During this period, it’s thought that the first luminous sources, such as stars, quasars, and galaxies, appeared in the universe, causing the previously neutral intergalactic medium, made mostly of hydrogen gas, to become ionized.</p>
<p>Prior to the appearance of the first stars, the universe was shrouded in darkness, and hydrogen, its most abundant element, was virtually invisible, embodying an energy state that was indistinguishable from the surrounding cosmic background radiation.</p>
<p>Scientists believe that when the first stars turned on, they provided ultraviolet radiation that caused changes to the hydrogen atoms’ distribution of energy states. These changes induced hydrogen’s single electron to spin in alignment or opposite to the spin of its proton, causing hydrogen as a whole to “decouple” from the background radiation. As a result, hydrogen gas began to either emit or absorb that radiation, at a characteristic wavelength of 21 centimeters, equivalent to a frequency of 1,420 megahertz. As the universe expanded over time, this radiation became “red-shifted” to lower frequencies. By the time this 21-centimeter radiation reached present-day Earth, it landed somewhere in the range of 100 megahertz.</p>
<p>Rogers and his colleagues have been using EDGES to try to detect hydrogen that existed during the very early evolution of the universe, in order to pinpoint when the first stars turned on.</p>
<p>“There is a great technical challenge to making this detection,” says Peter Kurczynski, program director for Advanced Technologies and Instrumentation, in the Division of Astronomical Sciences at the National Science Foundation, which has provided funding for the project over the past several years. “Sources of noise can be a thousand times brighter than the signal they are looking for. It is like being in the middle of a hurricane and trying to hear the flap of a hummingbird’s wing.”</p>
<p>The instrument, about the size of a small table, sits in a remote region of western Australia where there are very little humanmade radio signals to interfere with incoming radio waves from the distant universe. The antenna detects radio waves from the entire sky, and the researchers had originally tuned it to listen in at a frequency range of 100 to 200 megahertz.</p>
<p><strong>A switch hit </strong></p>
<p>However, when the researchers looked within this range, they initially failed to pick up much of any signal. They realized that theoretical models had predicted that primordial hydrogen should give off emissions within this range if the gas was hotter than the surrounding medium. But what if the gas was in fact colder? Models predict that the hydrogen should then absorb radiation more strongly in the 50 to 100 megahertz frequency range.</p>
<p>“As soon as we switched our system to this lower range, we started seeing things that we felt might be a real signature,” Rogers says.</p>
<p>Specifically, the researchers observed a flattened absorption profile, or a dip in the radio waves, at around 78 megahertz.</p>
<p>“We see this dip most strongly at about 78 megahertz, and that frequency corresponds to roughly 180 million years after the Big Bang,” Rogers says. “In terms of a direct detection of a signal from the hydrogen gas itself, this has got to be the earliest.”</p>
<p>The dip in radio waves was stronger and deeper than theoretical models predicted, suggesting that the hydrogen gas at the time was colder than previously thought. The radio waves’ profile also matches theoretical predictions of what would be produced if hydrogen were indeed influenced by the first stars.</p>
<p>“The signature of this absorption feature is uniquely associated with the first stars,” Lonsdale says. “Those stars are the most plausible source of radiation that would produce this signal.”</p>
<p>“It is unlikely that we’ll be able to see any earlier into the history of stars in our lifetimes,” lead author Bowman of ASU says. “This project shows that a promising new technique can work and has paved the way for decades of new astrophysical discoveries.”</p>
<p>The researchers say this new detection lifts the curtain on a previously obscure phase in the evolution of the universe.</p>
<p>“This is exciting because it is the first look into a particularly important period in the universe, when the first stars and galaxies were beginning to form,” Lonsdale says. “This is the first time anybody’s had any direct observational data from that epoch.”</p>
<p>This research was supported by funding from the National Science Foundation.</p>
Artist's rendering of the universe's first, massive, blue stars in gaseous filaments, with the cosmic microwave background (CMB) at the edges. Using radio observations of the distant universe, NSF-funded researchers Judd Bowman of Arizona State University, Alan Rogers of MIT, and others discovered the influence of such early stars on primordial gas. The team inferred the stars' presence from dimming of the CMB, a result of the gaseous filaments absorbing the stars' UV light. The CMB is dimmer than expected, indicating the filaments may have been colder than expected, possibly from interactions with dark matter. Image: N.R.Fuller/National Science FoundationAstronomy, Astrophysics, Haystack Observatory, Physics, Research, School of Science, space, Space, astronomy and planetary science, National Science Foundation (NSF)EAPS welcomes Heising-Simons fellow Ian Wonghttps://news.mit.edu/2018/mit-eaps-welcomes-2018-heising-simons-foundation-51-pegasi-b-postdoctoral-fellow-0207
The 51 Pegasi b Postdoctoral Fellowship provides junior scientists the opportunity to conduct theoretical, observational, and experimental research in planetary astronomy.Wed, 07 Feb 2018 16:00:00 -0500Helen Hill | EAPShttps://news.mit.edu/2018/mit-eaps-welcomes-2018-heising-simons-foundation-51-pegasi-b-postdoctoral-fellow-0207<p>The Department of Earth, Atmospheric and Planetary Sciences (EAPS) is looking&nbsp;forward to welcoming planetary scientist Ian Wong, one of the&nbsp;51 Pegasi b Postdoctoral Fellows for 2018 <a href="http://www.hsfoundation.org/new-class-51-pegasi-b-fellows-announced/">announced this week&nbsp;</a>by the Heising-Simons Foundation.</p>
<p>Named for the first exoplanet discovered orbiting a Sun-like star, the new 51 Pegasi b Fellowships are intended to give exceptional postdoctoral scientists the opportunity to conduct theoretical, observational, and experimental research in planetary astronomy.</p>
<p>Wong will be hosted at MIT by the Binzel Group in EAPS. Led by Margaret MacVicar Faculty Fellow and Professor of Planetary Sciences&nbsp;Richard P. Binzel, who is one of the world’s leading scientists in the study of asteroids and Pluto,&nbsp;the group’s research focuses on theory, computation, and data analysis of planetary bodies throughout the solar system.</p>
<p>Wong’s work seeks to decipher the history of our solar system by studying its most primitive bodies.&nbsp;</p>
<p>A visit to the Palomar Observatory as a first-year graduate student cemented Wong’s commitment to observation and hands-on data collection. His observational research focuses on small, icy asteroids in the middle and outer regions of our solar system. Astronomers consider these primitive bodies to be the building blocks of planets, providing a window into the earliest stages of our solar system — and perhaps even into the origins of life on Earth.</p>
<p>By studying the physical and chemical properties of these objects, Wong is working to infer details about the environment in which they formed, and uncover evidence that may support recent theories suggesting that the entire solar system once rearranged itself through a chaotic, dynamical event. Enhancing knowledge of our own solar system’s history in these ways can also help explain the observed diversity among exoplanet systems.</p>
<p>During his fellowship, Wong will investigate Kuiper Belt objects beyond the giant planets, as well as the Trojan and Hilda asteroids near Jupiter. He will compare the composition of these bodies to test theories of solar system formation and evolution. His planned research coincides withe the 2021 launch of Lucy, NASA’s first space mission to study Jupiter Trojans.&nbsp;</p>
<p>The Trojans&nbsp;are a population of primitive asteroids that orbit in tandem with Jupiter&nbsp;in two loose groups around the Sun, with one group always ahead of Jupiter in its path, the other always behind. At these two so-called Lagrange points, the bodies are stabilized by a gravitational balancing act between the Sun and Jupiter. Lucy’s complex path will take it to both clusters. Over 12 years, with boosts from Earth’s gravity, the spacecraft will journey to seven different asteroids in total — six Trojans and one from the Main Belt.&nbsp;</p>
<p>“These exciting worlds are remnants of the primordial material that formed the outer planets, and therefore hold vital clues to deciphering the history of the solar system,” Binzel&nbsp;says. Scientists hope that Lucy, like the human fossil for which the mission is named, will revolutionize the understanding of our origins.</p>
<p>“No other space mission in history has been launched to as many different destinations in independent orbits around our Sun. Lucy will show us, for the first time, the diversity of the primordial bodies that built the planets, opening up new insights into the origins of our Earth and ourselves,” Binzel says.</p>
<p>Wong explains that NASA’s Lucy mission “is a really big boon for my particular sub-field. On a fundamental level, it shows the importance of these not commonly studied objects. Throughout my fellowship, I hope to contribute important groundwork for interpreting the results of this probe.”&nbsp;</p>
<p>The big scientific question Wong will be chasing over the next three years is whether these asteroid populations are related to each other. While the traditional model of solar system evolution holds that these objects formed where they are, new insights have led scientists to theorize that an episode of dynamical instability completely rearranged the solar system.</p>
<p>“If that is the case, then all of the middle and outer solar system minor bodies should have formed within a single primordial population of asteroids beyond the ice giants, before being scattered into their current locations by the dynamical instability,” Wong says. “Exploring this is crucial to explaining details of solar system architecture that are left unanswered by the traditional model.”</p>
<p>Wong graduates from the California Institute of Technology in February 2018 with a PhD in planetary science. He holds a BA in linguistics from Princeton University.</p>
<p>The seven other 2018 51 Pegasi b Fellows and their host institutions are:&nbsp;Marta Bryan, University of California at Berkeley;&nbsp;Sivan Ginzburg, University of California at Berkeley; Thaddeus Komacek, University of Chicago;&nbsp;Aaron Rizzuto, University of Texas at Austin;&nbsp;Christopher Spalding, Yale University; Jason Wang, California Institute of Technology; and&nbsp;Ya-Lin Wu, University of Texas at Austin.</p>
<p>Each award provides up to $375,000 of support for independent research over three years,&nbsp;the time and freedom&nbsp;to establish distinction and leadership in the field, mentorship by an established faculty member at the host institution, and participation in an annual summit to develop professional networks, to exchange ideas, and to foster collaboration.</p>
<p>EAPS department head Robert van der Hilst says he&nbsp;is delighted that the Heising-Simons Foundation chose MIT as one of the five institutions to host the fellowship: “We are excited to welcome Ian to MIT. We are sure that his research will have an impact on our understanding of our solar system, and are honored and proud for EAPS to have been invited to host a Heising-Simons Foundation 51 Pegasi b Postdoctoral Fellow again this year.”</p>
<p>The Heising-Simons Foundation is a family foundation based in Los Altos, California. The foundation works with its many partners to advance sustainable solutions in climate and clean energy, enable groundbreaking research in science, enhance the education of our youngest learners, and support human rights for all people. More information about the foundation is available&nbsp;at&nbsp;<a href="http://www.heisingsimons.org/">www.heisingsimons.org</a>. To&nbsp;learn more about the fellowship, and its four inaugural fellows, please visit&nbsp;<a href="http://www.51pegasib.org/">www.51pegasib.org</a>.</p>
Ian Wong’s work seeks to decipher the history of our solar system by studying its most primitive bodies.Image courtesy of the Heising-Simons FoundationSchool of Science, Earth and atmospheric sciences, Graduate, postdoctoral, Exoplanets, Awards, honors and fellowships, Astronomy, Solar System, Research, Planetary scienceModeling the universehttps://news.mit.edu/2018/modeling-universe-Vogelsberger-IllustrisTNG-0131
MIT&#039;s Mark Vogelsberger and an international astrophysics team have created a new model pointing to black holes’ role in galaxy formation.Wed, 31 Jan 2018 19:00:00 -0500Julia Keller | School of Sciencehttps://news.mit.edu/2018/modeling-universe-Vogelsberger-IllustrisTNG-0131<p>A supercomputer simulation of the universe has produced new insights into how black holes influence the distribution of dark matter, how heavy elements are produced and distributed throughout the cosmos, and where magnetic fields originate.&nbsp;</p>
<p>Astrophysicists from MIT, Harvard University, the Heidelberg Institute for Theoretical Studies, the Max-Planck Institutes for Astrophysics and for Astronomy, and the Center for Computational Astrophysics gained new insights into the formation and evolution of galaxies by developing and programming a new simulation model for the universe — “Illustris - The Next Generation” or <a href="http://www.tng-project.org/">IllustrisTNG</a>.&nbsp;</p>
<p>Mark Vogelsberger, an assistant professor of physics at MIT and the MIT Kavli Institute for Astrophysics and Space Research, has been working to develop, test, and analyze the new IllustrisTNG simulations. Along with postdocs Federico Marinacci and Paul Torrey, Vogelsberger has been using IllustrisTNG to study the observable signatures from large-scale magnetic fields that pervade the universe.&nbsp;</p>
<p>Vogelsberger used the IllustrisTNG model to show that the turbulent motions of hot, dilute gases drive small-scale magnetic dynamos that can exponentially amplify the magnetic fields in the cores of galaxies — and that the model accurately predicts the observed strength of these magnetic fields.</p>
<p>“The high resolution of IllustrisTNG combined with its sophisticated galaxy formation model allowed us to explore these questions of magnetic fields in more detail than with any previous cosmological simulation," says Vogelsberger, an author on the three papers reporting the new work, published today in the <em>Monthly Notices of the Royal Astronomical Society</em>.</p>
<p><strong>Modeling a (more) realistic universe&nbsp;</strong></p>
<p>The IllustrisTNG project is a successor model to the original <a href="http://www.illustris-project.org/" target="_blank">Illustris simulation</a> developed by this same research team but has been updated to include some of the physical processes that play crucial roles in the formation and evolution of galaxies.&nbsp;</p>
<p>Like Illustris, the project models a cube-shaped piece of the universe. This time, the project followed the formation of millions of galaxies in a representative region of the universe with nearly 1 billion light years on a side (up from 350 million light years on a side just four years ago). lllustrisTNG is the largest hydrodynamic simulation project to date for the emergence of cosmic structures, says Volker Springel, principal investigator of IllustrisTNG and a researcher at Heidelberg Institute for Theoretical Studies, Heidelberg University, and the Max-Planck Institute for Astrophysics.</p>
<p>The cosmic web of gas and stars predicted by IllustrisTNG produces galaxies quite similar to the shape and size of real galaxies. For the first time, hydrodynamical simulations could directly compute the detailed clustering pattern of galaxies in space. In comparison with observational data — including the newest large galaxy surveys such as the Sloan Digital Sky Survey — IllustrisTNG demonstrates a high degree of realism, says Springel.&nbsp;</p>
<p>In addition, the simulations predict how the cosmic web changes over time, in particular in relation to the underlying backbone of the dark matter cosmos. “It is particularly fascinating that we can accurately predict the influence of supermassive black holes on the distribution of matter out to large scales,” says Springel. “This is crucial for reliably interpreting forthcoming cosmological measurements.”&nbsp;</p>
<p><strong>Astrophysics via code and supercomputers</strong>&nbsp;</p>
<p>For the project, the researchers developed a particularly powerful version of their highly parallel moving-mesh code AREPO and used it on the "<a href="https://www.hlrs.de/systems/cray-xc40-hazel-hen/">Hazel-Hen</a>" machine at the Supercomputing Center in Stuttgart, Germany's fastest mainframe computer.</p>
<p>To compute one of the two main simulation runs, more than 24,000 processors were used over the course of more than two months.</p>
<p>“The new simulations produced more than 500 terabytes of simulation data,” says Springel. “Analyzing this huge mountain of data will keep us busy for years to come, and it promises many exciting new insights into different astrophysical processes."&nbsp;</p>
<p><strong>Supermassive black holes squelch star formation</strong></p>
<p>In another study, Dylan Nelson, researcher at the Max-Planck Institute for Astrophysics, was able to demonstrate the important impact of black holes on galaxies.</p>
<p>Star-forming galaxies shine brightly in the blue light of their young stars until a sudden evolutionary shift quenches the star formation, such that the galaxy becomes dominated by old, red stars, and joins a graveyard full of old and dead galaxies.&nbsp;</p>
<p>“The only physical entity capable of extinguishing the star formation in our large elliptical galaxies are the supermassive black holes at their centers,” explains Nelson. “The ultrafast outflows of these gravity traps reach velocities up to 10 percent of the speed of light and affect giant stellar systems that are billions of times larger than the comparably small black hole itself.“</p>
<p><strong>New findings for galaxy structure</strong></p>
<p>IllustrisTNG also improves researchers' understanding of the hierarchical structure formation of galaxies. Theorists argue that small galaxies should form first, and then merge into ever-larger objects, driven by the relentless pull of gravity. The numerous galaxy collisions literally tear some galaxies apart and scatter their stars onto wide orbits around the newly created large galaxies, which should give them a faint background glow of stellar light.</p>
<p>These predicted pale stellar halos are very difficult to observe due to their low surface brightness, but IllustrisTNG was able to simulate exactly what astronomers should be looking for.&nbsp;</p>
<p>“Our predictions can now be systematically checked by observers,” says Annalisa Pillepich, a researcher at Max-Planck Institute for Astronomy, who led a further Illustris-TNG study. “This yields a critical test for the theoretical model of hierarchical galaxy formation.”&nbsp;</p>
Rendering of the gas velocity in a thin slice of 100 kiloparsec thickness (in the viewing direction), centered on the second most massive galaxy cluster in the TNG100 calculation. Where the image is black, the gas is hardly moving, while white regions have velocities that exceed 1,000 kilometers per second. The image contrasts the gas motions in cosmic filaments against the fast chaotic motions triggered by the deep gravitational potential well and the supermassive black hole sitting at its center.Image courtesy of the IllustrisTNG collaborationSchool of Science, Astrophysics, Physics, Kavli Institute, Research, Black holes, Dark matter, space, Space, astronomy and planetary sciencePrototypes for the new space agehttps://news.mit.edu/2018/prototypes-new-space-age-0126
The Media Lab Space Exploration Initiative shares results and next steps from its first zero gravity research mission.
Fri, 26 Jan 2018 17:29:01 -0500MIT Media Labhttps://news.mit.edu/2018/prototypes-new-space-age-0126<p>What happens when 20 researchers conduct 14 projects from entirely disparate fields of research over the course of 90 minutes — while floating in zero gravity? Thrills, learning, magic — and results.</p>
<p>This past November, the Media Lab Space Exploration Initiative chartered a flight with the Zero Gravity Corporation to conduct experiments that relied on the unique affordances of microgravity. Projects ranged across disciplines: design, architecture, engineering, biology, music, robotics, and beyond — manifesting the Initiative’s goal of democratizing access to space. On Jan. 23, the group reassembled to share the results of their projects and celebrate the success of the first flight, at a symposium for the MIT community.</p>
<p>“Space used to be for a very small number of people who had to study in a particular field and train for years. But space will soon be for everyone,” says Maria T. Zuber, MIT’s vice president for research and one of the initiative’s principal investigators. “The Media Lab students bring a creative view, and a lot of out-of-the-box thinking. If we expose those minds to space, we’ll have the benefit of their thinking about facilitating the opening up of the space frontier.”</p>
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<p><strong>Rapid prototypes, rapid results</strong></p>
<p>The January symposium demonstrated the remarkable diversity of research areas represented on the flight, and also underscored the far-reaching ideas behind the projects. Even by Media Lab standards it was an unusual assortment, running the gamut from peer-reviewed publications, to architectural modeling, to futuristic fashion. These researchers are imagining and prototyping for humanity's future in space, beyond the basic concerns of survival.</p>
<p>The researchers had only a few weeks to submit project proposals, and between two and five months to design their experiments and get them flight-ready and approved. Every proposal had to meet strict research criteria as well as stringent safety and operational standards. Each experiment had to be designed to run in only 20-30 seconds of zero gravity at a time, over the course of 90 minutes.</p>
<p>The results of the <a href="https://www.media.mit.edu/events/zero-gravity-flight-ml/" style="text-decoration:none;">14 research projects</a> that flew are as varied as their fields of inquiry. A few highlights:</p>
<p>Scratch in Space: Eric Schilling, of the Media Lab’s Scratch team, spent his time in microgravity playing games designed by members of the Scratch community, ages 8-15. He recorded his efforts and compiled them into a <a href="https://www.youtube.com/watch?v=Nbshe15M9G8">video</a>.</p>
<p>TESSERAE: The self-assembling architecture project of Ariel Ekblaw, of the Responsive Environments group, is aimed at a future need for low-cost orbiting space infrastructure. She published the results from the flight as part of a <a href="https://arc.aiaa.org/doi/pdf/10.2514/6.2018-0565" style="text-decoration:none;">technical paper</a> with AIAA (American Institute of Aeronautics and Astronautics) and presented the paper at their 2018 SciTech conference.</p>
<p>Search for Extra-Terrestrial Genomes (SETG): A project from MIT EAPS, headed by Maria Zuber, SETG is the first experiment to sequence DNA at lunar and Martian gravity. The team <a href="https://arxiv.org/abs/1712.05737" style="text-decoration:none;">published a paper</a> on their results, and are now developing a life-detection device that they hope to send to Mars one day.</p>
<p>Orbit Weaver: Fluid Interfaces group alumna Xin Liu’s Orbit Weaver is a hand-mounted device that shoots out a line and attaches to a surface with a magnet, theoretically allowing her to move with greater control in 3-D space. It’s paired with the Orbit Weaver Suit, a custom flight suit made of reflective material that enhances the performance-art aspect of Liu’s work. The project has been featured in <a href="http://thecreatorsproject.vice.cn/read/Orbit-Weaver-BODY-Liu-Xin" style="text-decoration:none;">Vice China’s <em>Creators Project</em></a>.</p>
<p>“I’m incredibly proud of all of the Media Lab projects and Lab students that have contributed,” says Ariel Ekblaw, the initiative’s founder and leader. “A typical zero gravity research flight is about a year in planning. That our participants were able to design and execute their experiments in just a few months really speaks to the culture of the Media Lab, both in terms of rapid prototyping and deployment, and the student-led, grassroots enthusiasm.”</p>
<p><strong>Next steps</strong></p>
<p>At the symposium, Ekblaw also outlined what’s ahead for the Space Exploration Initiative:</p>
<ul>
<li>
<p>Annual zero-gravity flight. The flight this past November will be the first of many; the goal is to get as many different projects from as many different research groups and areas of interest up and into zero gravity as possible.</p>
</li>
<li>
<p>Blue Origin flight, summer 2018. Six projects have been selected as payloads for a suborbital flight, allowing for more extended periods of microgravity.</p>
</li>
<li>
<p>International Space Station, winter 2019: Projecting for one to three payloads to board the ISS, allowing for consistent zero gravity conditions.</p>
</li>
</ul>
<p><strong>Beyond the Cradle</strong></p>
<p>In just a few weeks on March 10, Space Exploration will host its second <a href="https://www.media.mit.edu/events/beyond-the-cradle-2018/" style="text-decoration:none;">Beyond the Cradle event</a>, a gathering of students, scholars, and luminaries including astronauts, industry leaders, science fiction visionaries, and researchers. The event will be livestreamed; all are invited to watch and engage in imagining our space future.</p>
<div></div>
Noelle Bryan and Maria Zuber monitor their experiment while floating in zero gravity.Photo: Steve Boxall/ZERO-GMedia Lab, space, Space, astronomy and planetary science, School of Architecture and Planning, Research, Students, Faculty, Special events and guest speakersSolar eclipse caused bow waves in Earth&#039;s atmospherehttps://news.mit.edu/2018/solar-eclipse-caused-bow-waves-earths-atmosphere-0119
MIT Haystack Observatory researchers find that the moon&#039;s shadow created long-predicted ionospheric bow waves during the August eclipse.Fri, 19 Jan 2018 06:00:00 -0500Nancy Wolfe Kotary | MIT Haystack Observatoryhttps://news.mit.edu/2018/solar-eclipse-caused-bow-waves-earths-atmosphere-0119<p>The celebrated Great American&nbsp;Eclipse of August 2017 crossed the continental U.S. in 90 minutes, and totality lasted no longer than a few minutes at any one location. The event is well in the rear-view mirror now, but scientific investigation into the effects of the moon's shadow on the Earth's atmosphere is still being hotly pursued, and&nbsp;interesting new findings are surfacing at a rapid pace. These&nbsp;include&nbsp;significant observations by scientists at MIT’s Haystack Observatory in Westford, Massachusetts.</p>
<p>Eclipses are not particularly rare, but it is unusual for one to cross the entire continental U.S. as happened in August. By studying an eclipse’s effects on the electron content of the upper atmosphere, scientists are learning more about how our planet's complex and interlocked atmosphere responds to space weather events, such as solar flares and coronal mass ejections,&nbsp;that can have severe effects on signal information and communication paths, and can impact navigation and positioning services.</p>
<p>The ionosphere is the layer of the atmosphere containing charged particles created primarily by solar radiation.&nbsp;It allows long-distance radio wave propagation and communication over the horizon and affects essential satellite-based transmissions in navigation systems and on-board aircraft. Since the ionosphere is the medium in which radio waves travel and&nbsp;is affected by solar variations, understanding its features is important for our modern technological society. The ionosphere is host to a huge number of naturally occurring waves, from small to large in size and strength, and eclipse shadows in particular can leave behind a large number of newly created waves as they travel across the planet.</p>
<p>One kind of these new waves, known as ionospheric bow waves, has been predicted for more than 40 years to exist in the wake of an eclipse passage. Researchers at MIT's Haystack Observatory and the University of Tromsø in Norway confirmed the existence of ionospheric bow waves definitively for the first time during&nbsp;the August 2017 event. An international team led by Haystack Observatory scientists studied ionospheric electron content data collected by a network of more than 2,000 GNSS (Global Navigation Satellite System) receivers across the nation. Based on this work, Haystack’s Shunrong Zhang and colleagues published <a href="https://doi.org/10.1002/2017GL076054">an article </a>in December in the journal <em>Geophysical Research Letters</em> on the results showing the newly detected ionospheric bow waves.</p>
<div class="cms-placeholder-content-video"></div>
<p>Geospace research scientists at Haystack Observatory were able to observe the eclipse bow wave phenomenon for the first time in the atmosphere with unprecedented detail and accuracy, thanks to the vast network of extremely sensitive GNSS receivers now in place across the U.S. The observed ionospheric bow waves are much like those formed by&nbsp;a ship; the moon's shadow travels so quickly that it causes a sudden temperature change as the atmosphere is rapidly cooled and then reheated as the eclipse passes.&nbsp;</p>
<p>“The eclipse shadow has a supersonic motion which [generates] atmospheric bow waves, similar to a fast-moving river boat, with waves starting in the lower atmosphere and propagating into the ionosphere,” the&nbsp;description by Zhang and his colleagues states.&nbsp;“Eclipse passage generated clear ionospheric bow waves in electron content disturbances emanating from totality primarily over central/eastern United States. Study of wave characteristics reveals complex interconnections between the sun, moon, and Earth's neutral atmosphere and ionosphere.”</p>
<p>GNSS receivers collect very accurate, high-resolution data on the total electron content (TEC) of the ionosphere. The rich detail provided by this data informed <a href="https://doi.org/10.1002/2017GL075774">a separate study on eclipse effects</a> in the same issue of <em>Geophysical Research Letters</em> by the Haystack research team and international colleagues. Haystack Observatory Associate Director&nbsp;and lead author Anthea Coster and her co-authors describe the continental size and timing of eclipse-triggered TEC depletions observed over the U.S. and observed increased TEC over the Rocky Mountains that is likely related to the generation of mountain waves in the lower atmosphere during the eclipse. The reason for this effect — which was not predicted or anticipated before the eclipse — is being investigated by the geospace science community.</p>
<p>“Since the first days of radio communications more than 100 years ago, eclipses have been known to have large and sometimes unanticipated effects on the ionized part of Earth’s atmosphere and the signals that pass through it,” says Phil Erickson, assistant director at Haystack and lead for the atmospheric and geospace sciences group. “These new results from Haystack-led studies are an excellent example of how much still remains to be learned about our atmosphere and its complex interactions through observing one of nature’s most spectacular sights — a giant active celestial experiment provided by the sun and moon. The power of modern observing methods, including radio remote sensors distributed widely across the United States, was key to revealing these new and fascinating features.”</p>
<p><em>The Haystack eclipse studies, including the bow wave observations, drew the attention of national science media outlets, including <a href="https://news.nationalgeographic.com/2017/12/solar-eclipses-earth-bow-waves-atmosphere-space-science/">National Geographic</a></em>, <em><a href="http://www.newsweek.com/august-solar-eclipse-created-bow-waves-earths-atmosphere-phenomenon-never-seen-758831">Newsweek</a></em>, <a href="https://gizmodo.com/the-august-eclipse-left-a-wake-in-the-earths-upper-atmo-1821503369">Gizmodo</a>, and many others. One of Zhang’s readers, an eighth grader from Minnesota, asked some interesting questions:</p>
<p><strong>Q: </strong>Was there any prior evidence to show that the waves would be arriving during the eclipse?</p>
<p><strong>A:</strong> There were prior studies on the waves based on very limited spatial coverage of the observations. The Great American Eclipse provided unprecedented spatial coverage to view unambiguously the complete wave structures.</p>
<p><strong>Q:</strong> Did these waves emit any seismic activity? Did they have a frequency that they could be detected on?</p>
<p><strong>A:&nbsp;</strong>No, they didn’t. In fact we believe these waves were originated from the middle atmosphere [about&nbsp;50 kilometers]&nbsp;but we observed them in the upper atmosphere at approximately 300 kilometers. They were very weak-pressure fluctuations if we observe the waves from the ground. This kind of wave was produced by eclipse-related cooling processes; there might be other ways to induce similar waves in the upper atmosphere.</p>
<p><strong>Q: </strong>On the path of totality, were the waves stronger? Did they have any different effect anywhere else?</p>
<p><strong>A:&nbsp;</strong>Yes, we found that they existed mostly along and within a few hundreds of kilometers from the totality central path. They were first seen in central U.S., then vanished in the central-eastern U.S. They were able to travel for about one hour at a speed of approximately 300 meters per second, slower than the moon shadow’s speed.</p>
<p>Haystack scientists will continue to analyze atmospheric data from the eclipse and expect to report other findings shortly. The next major eclipse across North America will occur in April 2024.</p>
<p>GPS TEC data products and access through the Madrigal distributed data system are provided to the community by MIT with support from U.S. National Science Foundation grant AGS-1242204 and NASA grant NNX17AH71G for eclipse scientific support.</p>
This graphic shows atmospheric bow waves forming during the August 2017 eclipse over the continental United States.Image: Shunrong Zhang/Haystack ObservatoryEarth and atmospheric sciences, Space, astronomy and planetary science, Research, Haystack ObservatoryTwo from AeroAstro named to Aviation Week&#039;s “20 Twenties” for 2018https://news.mit.edu/2018/mit-aeroastro-aguilar-brown-named-aviation-week-20-twenties-0117
Grad students Alexa Aguilar and Arthur J. Brown receive honor that recognizes outstanding student academic performance, civic contributions, and research.Wed, 17 Jan 2018 14:00:00 -0500Bill Litant | Aeronautics and Astronauticshttps://news.mit.edu/2018/mit-aeroastro-aguilar-brown-named-aviation-week-20-twenties-0117<p>MIT aeronautics and astronautics graduate students Alexa Aguilar and Arthur J. Brown have been selected as recipients of <a href="http://aviationweek.com/future-aerospace/aviation-week-network-announces-20-twenties-winners-2018">Aviation Week Network’s</a> 2018 “Tomorrow’s Technology Leaders: The 20 Twenties” awards.</p>
<p>The awards recognize 20 students nominated by universities for academic performance, civic contributions, research, or design projects. The program is part of an effort to create and awareness by technology hiring managers, students, and faculty of elements that contribute to business and academic success.</p>
<p>Aguilar works in AeroAstro’s <a href="http://starlab.mit.edu/">Space Telecommunications, Astronomy, and Radiation Laboratory</a> (STAR Lab) on Cubesat Lasercommunication Infrared CrosslinK, a cubesat mission collaboration including NASA's Ames Research Center, the University of Florida, and MIT. A&nbsp;mission objective is to demonstrate a laser crosslink between two spacecraft at 20 megabits per second.</p>
<p>“I’m responsible for managing the optical link budgets, performing a trade study on receivers using a time-to-digital converter versus a traditional analog-to-digital converter, and potentially designing a novel optical receiver to replace commercial off-the-shelf components,” Aguilar says. “For this mission, I helped with the engineering model assembly that identified problem areas in the initial design, which were later fixed for the flight mode.”</p>
<p>Professor and STAR Lab Director Kerri Cahoy says&nbsp;Aguilar&nbsp;“has been supporting our nanosatellite laser communications project sponsored by NASA, and she continues to support other MIT projects that she worked on in the past.”</p>
<p>Cahoy&nbsp;praises&nbsp;Aguilar for her “sharp intellect, high productivity, cheerful energy, and outreach and advocacy for space exploration and innovation, which have made an impact on our group and the department.”</p>
<p>Brown’s research focuses on on-demand aviation —&nbsp;specifically, an air taxi service using small, autonomous, vertical-takeoff-and-landing, battery-powered electric aircraft.</p>
<p>“The proposed service offers numerous advantages over existing transport solutions, including greatly reduced commute times, by avoiding gridlock; lower energy costs, due to the use of electricity instead of gasoline; reduced environmental impact in terms of noise, greenhouse gases, lead, and other emissions, and due to the use of electric propulsion; and lower or no pilot operating costs, due to autonomy,”&nbsp;Brown says.</p>
<p>Brown is an officer of MIT’s <a href="https://www.media.mit.edu/publications/the-academy-of-courageous-minority-engineers-a-model-for-supporting-minority-graduate-students-in-the-completion-of-science-and-engineering-degrees/">Academy of Courageous Minority Engineers</a> and a member of the <a href="http://gsc.mit.edu/">Graduate Student Council’s</a> Diversity and Inclusion subcommittee.</p>
<p>“In my opinion, Arthur’s work exceeds all published investigation and produces tools to make industry-grade decisions for on-demand aviation,” says AeroAstro Professor Wesley Harris, Brown’s thesis advisor.</p>
<p>Harris also praises&nbsp;Brown’s involvement with organizations focusing on underrepresented students. “He’s influenced the MIT administration to structure programs and activities that enable advancement of underrepresented students, and done so with a positive, firm approach,” he says.</p>
<p>Aviation Week Network president Greg Hamilton says 20 Twenties&nbsp;recognition is built on “three pillars of what the aerospace industry values most: learning, civic service, and high-value research. This year’s winners reflect these pillars, while bringing to the fore the innovation and creativity that are hallmarks for this generation.”</p>
<p>Aguilar and Brown will be honored at Aviation Week’s Annual Laureates Awards on&nbsp;March 1 in Washington.</p>
Aviation Week Network “20 Twenties” award recipient Alexa Aguilar is a grad student working in AeroAstro’s Space Telecommunications, Astronomy, and Radiation Laboratory (STAR Lab) on the Cubesat Lasercommunication Infrared CrosslinK mission. She assisted with an engineering model assembly that identified problem areas in the initial design.Photo: William LitantAeronautics and Astronautics, Awards, honors and fellowships, Autonomous vehicles, School of Engineering, NASA, Satellites, graduate, Graduate, postdoctoral, space, Space, astronomy and planetary science, Diversity and inclusionCitizen scientists discover five tightly packed exoplanets https://news.mit.edu/2018/citizen-scientists-discover-five-tightly-packed-exoplanets-0111
The planetary system’s dense configuration gives clues to its formationThu, 11 Jan 2018 14:29:59 -0500Jennifer Chu | MIT News Officehttps://news.mit.edu/2018/citizen-scientists-discover-five-tightly-packed-exoplanets-0111<p>Five new planets have been discovered outside our solar system, all orbiting a sun-like star located within the constellation Aquarius, nearly 620 light years from Earth. The alien worlds are considered super-Earths, sizing in at two to three times larger than our own blue planet.</p>
<p>All five exoplanets are likely scorchingly hot: Each planet comes incredibly close to its star, streaking around in just 13 days at most — a whirlwind of an orbit compared with Earth’s 365-day year.</p>
<p>The planets also appear to orbit their star in concentric circles, forming a tightly packed planetary system, unlike our own elliptical, far-flung solar system. In fact, the size of each planet’s orbit appears to be a ratio of the other orbits — a configuration astronomers call “resonance” — suggesting that all five planets originally formed together in a smooth, rotating disc, and over eons migrated closer in toward their star.&nbsp;</p>
<p>These new findings have been accepted to the <em>Astrophysical Journal</em> and were presented today by researchers from MIT and Caltech at the meeting of the American Astronomical Society.</p>
<p><strong>“Leveraging the human cloud”</strong></p>
<p>The researchers say the credit for this planetary discovery goes mainly to the citizen scientists — about 10,000 from the around the world — who pored through publicly available data from K2, a follow-on to NASA’s Kepler Space Telescope mission, which since 2009 has observed the sky for signs of Earth-like planets orbiting sun-like stars.</p>
<p>In 2013, a malfunction in one of the spacecraft’s wheels forced Kepler to end its continuous observations. However, the following year, scientists reprogrammed the spacecraft’s thrusters and remaining wheels, enabling the telescope to point at certain parts of the sky for limited periods. Scientists dubbed this new phase of the mission “K2,” and they have been collecting data from the rejiggered telescope for the last three years.</p>
<p>K2’s data comprises light curves — graphs of light intensity from individual stars in the sky. A dip in starlight indicates a possible transit, or crossing, of an object such as a planet in front of its star.</p>
<p>The original Kepler mission was managed mostly by a dedicated team of trained scientists and astronomers who were tasked with analyzing incoming data, looking for transits, and classifying exoplanet candidates. In contrast, K2 has been driven mainly by decentralized, community-led efforts. &nbsp;</p>
<p>In 2017, Ian Crossfield, assistant professor of physics at MIT, who at the time was a Sagan Fellow at the University of California at Santa Cruz, worked with fellow astronomer Jesse Christiansen at Caltech to make the K2 data public and enlist as many volunteers as they could in the search for exoplanets.</p>
<p>The team used a popular citizen-scientist platform called <a href="https://www.zooniverse.org/">Zooniverse</a> to create its own project, dubbed Exoplanet Explorers. The project was inspired by a similar effort via Zooniverse called Planet Hunters, which has enabled users to sift through and classify both Kepler and K2 data.</p>
<p>For the Exoplanet Explorers project, Crossfield and Christiansen first ran a signal-detection algorithm to identify potential transit signals in the K2 data, then made those signals available on the Zooniverse platform. They designed a training program to first teach users what to look for in determining whether a signal is a planetary transit. Users could then sift through actual light curves from the K2 mission and click “yes” or “no,” depending on whether they thought the curve looked like a transit.</p>
<p>At least 10 users would have to look at a potential signal, and 90 percent of these users would have to vote “yes,” for Crossfield and Christiansen to consider the signal for further analysis.</p>
<p>“We put all this data online and said to the public, ‘Help us find some planets,’” Crossfield says. “It’s exciting, because we’re getting the public excited about science, and it’s really leveraging the power of the human cloud.”</p>
<p><strong>Planetary wheat and chaff</strong></p>
<p>Several months into working with Zooniverse to get Exoplanet Explorers up and running, the researchers got a call from an Australian television program that was offering to feature the project on live television. The team scrambled to launch the effort, and over two days in April, as the program was broadcast live, Exoplanet Explorers drew 10,000 users who started sifting through the K2 data. Over 48 hours, the users made nearly 2 million classifications from the available light curves.</p>
<p>Crossfield and Christiansen, along with NASA astronomer Geert Barentsen, looked more closely at the classifications flagged by the public and determined that many of them were indeed objects of interest. In particular, the effort identified 44 Jupiter-sized, 72 Neptune-sized, and 44 Earth-sized planets, as well as 53 so-called super Earths, which are larger than Earth but smaller than Neptune.</p>
<p>One set of signals in particular drew the researchers’ interest. The signals appeared to resemble transits from five separate planets orbiting a single star, 190 parsecs, or 620 light years, away.</p>
<p>To follow up, they collected supporting data of the star taken previously from ground-based telescopes, which helped them to estimate the star’s size, mass, and temperature. They then took some additional measurements to ensure that it was indeed a single star, and not a cluster of stars.</p>
<p>By looking closely at the light curves associated with the star, the researchers determined that it was “extremely likely” that five planet-like objects were crossing in front of the star. From their estimates of the star’s parameters, they inferred the sizes of the five planets — between 2 and 2.9 times the size of the Earth — along with their orbits.</p>
<p>The new system, which they have dubbed K2-138, represents the first planetary system identified by citizen scientists using K2 data. Crossfield says as more data becomes available from other observational campaigns, he hopes scientists and citizens can work together to uncover new astrophysical phenomena.</p>
<p>“It turns out the world is big enough that there’s a lot of people who are interested in doing some amateur science,” Crossfield says. “And the human eye in many cases is very effective in separating the planetary wheat from the nonplanetary chaff.”</p>
<p>In particular, he envisions that the public will one day be able to analyze data taken by TESS, the Transiting Exoplanet Survey Satellite, which is set to launch later this year. It’s an MIT-led mission that will survey the entire sky for exoplanets orbiting the brightest stars.</p>
<p>“We’re looking forward to more discoveries in the near future,” Crossfield says. “We hope that the TESS mission, which MIT is leading, will also be able to engage the public in this way.”</p>
Five new planets have been discovered outside our solar system, all orbiting a sun-like star located within the constellation Aquarius, nearly 620 light years from Earth. The alien worlds are considered super-Earths, sizing in at two to three times larger than our own blue planet. Image: Christine Daniloff/MITAstronomy, Astrophysics, Department of Physics, Exoplanets, Kavli Institute, Space, astronomy and planetary science, Research, School of Science, Planetary scienceDrug manufacturing that’s out of this worldhttps://news.mit.edu/2018/startup-zaiput-flow-technologies-drug-manufacturing-space-0105
Continuous-flow chemistry device used for drug production could find use in long-duration space missions.Fri, 05 Jan 2018 00:00:00 -0500Rob Matheson | MIT News Officehttps://news.mit.edu/2018/startup-zaiput-flow-technologies-drug-manufacturing-space-0105<p>Liquid-liquid separation and chemical extraction are key processes in drug manufacturing&nbsp;and many other industries, including oil and gas, fragrances, food, wastewater filtration, and biotechnology.</p>
<p>Three years ago, MIT spinout Zaiput Flow Technologies launched a novel continuous-flow liquid-liquid separator that makes those processes faster, easier, and more efficient. Today, nine pharmaceutical giants and a growing number of academic labs and small companies use the separator.</p>
<p>Having proved its efficacy on Earth, the separator is now being tested as a tool for manufacturing drugs and synthesizing chemicals in outer space.</p>
<p>In 2015, Zaiput won a Galactic Grant from the Center for the Advancement of Science in Space that allows companies to test technologies on the International Space Station (ISS). On Dec. 15, after two years of development and preparation, Zaiput launched its separator in a SpaceX rocket as part of the CRS-13 cargo resupply mission that will last one month.</p>
<p>As long-duration space travel and extraterrestrial habitation becomes a potential reality, it’s important to find ways to synthesize chemicals for drugs, food, fuels, and other products in space that may be important for those missions, says Zaiput co-founder and CEO Andrea Adamo SM ’03, who co-invented the separator in the lab of Klavs Jensen, the Warren K. Lewis Professor of Chemical Engineering. Notably, Zaiput’s separator, called SEP-10, separates liquids without the need for gravity, which is a trademark of traditional methods.</p>
<p>“When people go on deep space explorations, or maybe to Mars, these are multiyear missions,” Adamo says. “But how do you synthesize chemicals for drugs and other products without gravity? We have that answer. Testing our unit in space will show that what we have done on Earth is fully exportable to space.”</p>
<p>Results from the ISS experiments will prove that the device indeed functions in zero-gravity, which is basically impossible to verify on Earth. And, they will help the startup refine the device, Adamo says: “MIT strives for excellence and we inherited that model — we’re still striving for excellence.”</p>
<p><strong>Surface forces</strong></p>
<p>In traditional liquid-liquid separators, a mixture of two liquids of different densities is fed into a funnel-shaped settling tank. The heavier liquid sinks and can be drained out through a valve, away from the lighter liquid, which stays on top. But the separation process is time-consuming, and some chemicals can decay or become unstable while sitting in the tank.</p>
<p>Instead of leveraging gravity, Zaiput’s separator uses surface forces to attract or repel a liquid from a membrane. As an example, consider a nonstick pan: Oil spreads on the pan, but water beads up because it has an affinity to bond with the polymer covering the pan, while oil does not.</p>
<p>Zaiput’s separator uses the same principle. A mixture of liquids is pumped through a feed tube and travels to a porous polymer membrane. One liquid is drawn to the surface of the membrane, while the other is repelled. An internal mechanical pressure controller maintains a slight pressure differential between one side of the membrane and the other. This differential is just enough to push the attracted liquid through the porous membrane without pushing the repelled one. The attracted liquid then goes out through one tube, while allowing the repelled liquid to flow out through a separate tube. Flow rates range from 0 to 12 milliliters per minute.</p>
<p>“If you want to use this for a continuous operation in a reliable way, you have to carefully control pressure conditions across membranes,” Adamo says. “You want a little bit of pressure, so the chemical goes through, but not too much to push through the unwanted liquid. The internal controller ensures this happens at all times.”</p>
<p>Zaiput’s separator also improves chemical extraction, which is different from liquid separation. Imagine working with a mixture of wine and oil. Liquid separation means separating the mixture into individual flows, of wine and oil. Extraction, however, means removing the ethanol chemical from the wine, along with separating the liquids, which is of interest to chemists.</p>
<p>For chemical extraction, a “feed” liquid that contains a target chemical for extraction and a “solvent” — which is incapable of mixing with the feed liquid —&nbsp;are combined in a tube that flows toward the separation device. The solvent captures the target chemical from the feed because the chemical is soluble in it; the separation devices then separate two streams, with the solvent containing the target chemical. In the wine-oil example, the ethanol would be removed by the oil solvent.</p>
<p>Zaiput units can be equipped with different types of membranes to achieve specific effects, or connected in a series of units.</p>
<p>Importantly, Adamo says, Zaiput’s continuous-flow, membrane-based separator allows for separation of emulsions, whereby small droplets of one liquid end up in the other liquid, never fully separating. “We don’t have that issue, because we don’t need to wait for liquids to settle,” Adamo says. “We are the only technology that provides continuous separation, can readily separate emulsions, and is also designed for safety, so if you’re dealing with explosive or toxic substances, you can process them quickly.”</p>
<p><strong>Beautifying and scaling up</strong></p>
<p>Adamo came to MIT in the early 2000s as a civil engineer. Conducting research at MIT and being exposed to the Institute’s entrepreneurial ecosystem, however, “changed my horizons,” he says. “I wanted to be in a field where I could bring technology to the world through a startup.”</p>
<p>Civil engineering had some limits in that regard, so Adamo started experimenting in the fast-moving field of microfluidics, working as a researcher in the lab of Jensen, a pioneer of flow chemistry. Inspired by Jensen’s previous research into surface forces, Adamo began designing a small, membrane-based separation device equipped with a precise pressure controller that maintained exact conditions for separation. This first prototype consisted of two bulky plastic pieces bolted together. “It was really ugly,” Adamo says.</p>
<p>But showcasing the prototype to colleagues at MIT, he found that despite its unaesthetic appearance, the device had commercial potential. “The innovation was not just good for the lab, but also for general public,” he says. “I started looking into business propositions.” (So far, the research has also produced <a href="http://pubs.acs.org/doi/10.1021/ie401180t">two</a> <a href="http://pubs.acs.org/doi/abs/10.1021/acs.iecr.7b00434">papers</a> co-authored by Jensen, Adamo, and other MIT researchers in <em>Industrial &amp; Engineering Chemistry</em> <em>Research</em>.)</p>
<p>In 2013, Adamo co-founded Zaiput with partner and Harvard University biochemist Jennifer Baltz, now Zaiput’s chief operating officer, with help from MIT’s Venture Mentoring Service and other MIT services.</p>
<p>The startup designed a far more appealing product. Growing up in Italy, Adamo says, he was always surrounded by beautiful, colorful scenery and objects. He used that background as inspiration for the separator’s design, turning the prototype into a series of handheld, colorful blocks. Lab units are orange; larger units are purple, gold, or lime green. There is also color coding for different devices that are made of different materials.</p>
<p>“Customers visit labs and these devices pop out,” Adamo says. “Function is key, but when you take an object in your hands, it has to feel nice. It has to be pleasing to the eye and, in a commercial sense, distinctive.”</p>
<p>Currently, Zaiput is developing a production-scale device with a flow rate of 3,000 milliliters per minute, for larger-scale drug manufacturing. The startup is also hoping to more efficiently tackle very complex chemical extractions. Today, this involves repeating chemical extraction processes multiple times in massive columns, about 100 feet high, to ensure as much of the target chemical has been extracted from a liquid. But Zaiput hopes it can do the same with a small system of combined modular units. Additionally, the startup hopes to bring the device to traditional batch-separation users, notably those who still work with settling tanks.</p>
<p>“The next challenges are bigger-scale development, more complex extraction, and reaching out to traditional users to empower them with new technologies,” Adamo says.</p>
In the continuous-flow liquid-liquid separator developed by MIT spinout Zaiput Flow Technologies, liquid mix (blue and pink) is pumped through a feed tube to a porous polymer membrane (dotted line). One liquid (pink) is drawn to the surface of the membrane, while the other (blue) is repelled. An internal mechanical pressure controller maintains a slight pressure differential between the two sides of the membrane. This pushes the attracted liquid through the membrane without the repelled one, sending each liquid through separate tubes.Courtesy of Zaiput Flow TechnologiesInnovation and Entrepreneurship (I&E), Startups, Alumni/ae, Chemical engineering, School of Engineering, Chemistry, Drug development, Pharmaceuticals, Manufacturing, Oil and gas, Industry, Food, Water, Agriculture, Biological engineering, Space, astronomy and planetary scienceCleaner air, longer lives https://news.mit.edu/2017/cleaner-air-longer-lives-organic-aerosols-1225
Research shows the Clean Air Act was likely responsible for a dramatic decline in atmospheric organic aerosol.Mon, 25 Dec 2017 15:00:00 -0500Carolyn Schmitt | Department of Civil and Environmental Engineeringhttps://news.mit.edu/2017/cleaner-air-longer-lives-organic-aerosols-1225<p>The air we breathe contains particulate matter from a range of natural and human-related sources. Particulate matter is responsible for thousands of premature deaths in the United States each year, but legislation from the U.S. Environmental Protection Agency (EPA) is credited with significantly decreasing this number, as well as the amount of particulate matter in the atmosphere. However, the EPA may not be getting the full credit they deserve: New research from MIT’s Department of Civil and Environmental Engineering (CEE) proposes that the EPA’s legislation may have saved even more lives than initially reported.</p>
<p>“In the United States, the number of premature deaths associated with exposure to outdoor particulate matter exceeds the number of car accident fatalities every year. This highlights the vital role that the EPA plays in reducing the exposure of people living in the United States to harmful pollutants,” says Colette Heald, associate professor in CEE&nbsp;and the Department of Earth, Atmospheric and Planetary Sciences.</p>
<p>The EPA’s 1970 Clean Air Act and amendments in 1990 address the health effects of particulate matter, specifically by regulating emissions of air pollutants and promoting research into cleaner alternatives. In 2011 the EPA announced that the legislation was responsible for a considerable decrease in particulate matter in the atmosphere, estimating that over 100,000 lives were saved every year from 2000 to 2010. However, the report did not consider organic aerosol, a major component of atmospheric particulate matter, to be a large contributor to the decline in particulate matter during this period. Organic aerosol is emitted directly from fossil fuel combustion (e.g. vehicles), residential burning, and wildfires but is also chemically produced in the atmosphere from the oxidation of both natural and anthropogenically emitted hydrocarbons.</p>
<p>The CEE research team, including Heald; Jesse Kroll, an associate professor of CEE and of chemical engineering; David Ridley, a research scientist in CEE; and Kelsey Ridley SM ’15, looked at surface measurements of organic aerosol from across the United States from 1990 to 2012, creating a comprehensive picture of organic aerosol in the United States.</p>
<p>“Widespread monitoring of air pollutant concentrations across the United States enables us to verify changes in air quality over time in response to regulations. Previous work has focused on the decline in particulate matter associated with efforts to reduce acid rain in the United States. But to date, no one had really explored the long-term trend in organic aerosol,” Heald says.&nbsp;</p>
<p>The MIT researchers found a more dramatic decline in organic aerosol across the U.S. than previously reported, which may account for more lives saved than the EPA anticipated. Their work showed that these changes are likely due to anthropogenic, or human, behaviors. The paper is published this week in <em>Proceedings of the National Academy of Sciences</em>.</p>
<p>“The EPA report showed a very large impact from the decline in particulate matter, but we were surprised to see a very little change in the organic aerosol concentration in their estimates,” explains Ridley. “The observations suggest that the decrease in organic aerosol had been six times larger than estimated between 2000 and 2010 in the EPA report.”</p>
<p>Using data from the Interagency Monitoring of Protected Visual Environments (IMPROVE) network the researchers found that organic aerosol decreased across the entire country in the winter and summer seasons. This decline in organic aerosol is surprising, especially when considering the increase in wildfires. But the researchers found that despite the wildfires, organic aerosols continue to decline.&nbsp;</p>
<p>The researchers also used information from the NASA Modern-Era Retrospective analysis for Research and Applications to analyze the impact of other natural influences on organic aerosol, such as precipitation and temperature, finding that the decline would be occurring despite cloud cover, rain, and temperature changes.&nbsp;</p>
<p>The absence of a clear natural cause for the decline in organic aerosol suggests the decline was the result of anthropogenic causes. Further, the decline in organic aerosol was similar to the decrease in other measured atmospheric pollutants, such as nitrogen dioxide and carbon monoxide, which are likewise thought to be due to EPA regulations. Also, similarities in trends across both urban and rural areas suggest that the declines may also be the result of behavioral changes stemming from EPA regulations.</p>
<p>By leveraging the emissions data of organic aerosol and its precursors, from both natural and anthropogenic sources, the researchers simulated organic aerosol concentrations from 1990 to 2012 in a model. They found that more than half of the decline in organic aerosol is accounted for by changes in human emissions behaviors, including vehicle emissions and residential and commercial fuel burning.&nbsp;</p>
<p>“We see that the model captures much of the observed trend of organic aerosol across the U.S., and we can explain a lot of that purely through changes in anthropogenic emissions. The changes in organic aerosol emissions are likely to be indirectly driven by controls by the EPA on different species, like black carbon from fuel burning and nitrogen dioxide from vehicles,” says Ridley. ”This wasn’t really something that the EPA was anticipating, so it’s an added benefit of the Clean Air Act.”</p>
<p>In considering mortality rates and the impact of organic aerosol over time, the researchers used a previously established method that relates exposure to particulate matter to increased risk of mortality through different diseases such as cardiovascular disease or respiratory disease. The researchers could thus figure out the change in mortality rate based on the change in particulate matter. Since the researchers knew how much organic aerosol is in the particulate matter samples, they were able to determine how much changes in organic aerosol levels decreased mortality.</p>
<p>“There are costs and benefits to implementing regulations such as those in the Clean Air Act, but it seems that we are reaping even greater benefits from the reduced mortality associated with particulate matter because of the change in organic aerosol,” Ridley says. “There are health benefits to reducing organic aerosol further, especially in urban locations. As we do, natural sources will contribute a larger fraction, so we need to understand how they will vary into the future too.”</p>
<p>This research was funded, in part, by the National Science Foundation, the National Aeronautics and Space Administration, and the National Oceanic and Atmospheric Administration.</p>
MIT researchers found a more dramatic decline in organic aerosol across the U.S. than previously reported, which may account for more lives saved than the U.S. Environmental Protection Agency anticipated in a 2011 report on the Clean Air Act and amendments. The study found that the decline is likely due to human behaviors. Photo: Andrius K / ShutterstockSchool of Engineering, School of Science, Civil and environmental engineering, Chemical engineering, EAPS, Research, Earth and atmospheric sciences, Policy, Environment, Emissions, National Science Foundation (NSF), NASAScientists observe supermassive black hole in infant universehttps://news.mit.edu/2017/scientists-observe-supermassive-black-hole-infant-universe-1206
Findings present a puzzle as to how such a huge object could have grown so quickly.Wed, 06 Dec 2017 13:00:00 -0500Jennifer Chu | MIT News Officehttps://news.mit.edu/2017/scientists-observe-supermassive-black-hole-infant-universe-1206<p>A team of astronomers, including two from MIT, has detected the most distant supermassive black hole ever observed. The black hole sits in the center of an ultrabright quasar, the light of which was emitted just 690 million years after the Big Bang. That light has taken about 13 billion years to reach us — a span of time that is nearly equal to the age of the universe.</p>
<p>The black hole is measured to be about 800 million times as massive as our sun — a Goliath by modern-day standards and a relative anomaly in the early universe.</p>
<p>“This is the only object we have observed from this era,” says Robert Simcoe, the Francis L. Friedman Professor of Physics in MIT’s Kavli Institute for Astrophysics and Space Research. “It has an extremely high mass, and yet the universe is so young that this thing shouldn’t exist. The universe was just not old enough to make a black hole that big. It’s very puzzling.”</p>
<p>Adding to the black hole’s intrigue is the environment in which it formed: The scientists have deduced that the black hole took shape just as the universe was undergoing a fundamental shift, from an opaque environment dominated by neutral hydrogen to one in which the first stars started to blink on. As more stars and galaxies formed, they eventually generated enough radiation to flip hydrogen from neutral, a state in which hydrogen’s electrons are bound to their nucleus, to ionized, in which the electrons are set free to recombine at random. This shift from neutral to ionized hydrogen represented a fundamental change in the universe that has persisted to this day.</p>
<p>The team believes that the newly discovered black hole existed in an environment that was about half neutral, half ionized.</p>
<p>“What we have found is that the universe was about 50/50 — it’s a moment when the first galaxies emerged from their cocoons of neutral gas and started to shine their way out,” Simcoe says. “This is the most accurate measurement of that time, and a real indication of when the first stars turned on.”</p>
<p>Simcoe and postdoc Monica L. Turner are the MIT co-authors of a paper detailing the results, published today in the journal <em>Nature</em>. The other lead authors are from the Carnegie Institution for Science, in Pasadena, California.</p>
<p><strong>A shift, at high speed</strong></p>
<p>The black hole was detected by Eduardo Bañados, an astronomer at Carnegie, who found the object while combing through multiple all-sky surveys, or maps of the distant universe. Bañados was looking in particular for quasars — some of the brightest objects in the universe, that consist of a supermassive black hole surrounded by swirling, accreting disks of matter.</p>
<p>After identifying several objects of interest, Bañados focused in on them using an instrument known as FIRE (the Folded-port InfraRed Echellette), which was built by Simcoe and operates at the 6.5-meter-diameter Magellan telescopes in Chile. FIRE is a spectrometer that classifies objects based on their infrared spectra. The light from very distant, early cosmic objects shifts toward redder wavelengths on its journey across the universe, as the universe expands. Astronomers refer to this Doppler-like phenomenon as “redshift”; the more distant an object, the farther its light has shifted toward the red, or infrared end of the spectrum. The higher an object’s redshift, the further away it is, both in space and time.</p>
<p>Using FIRE, the team identified one of Bañados’ objects as a quasar with a redshift of 7.5, meaning the object was emitting light around 690 million years after the Big Bang. Based on the quasar’s redshift, the researchers calculated the mass of the black hole at its center and determined that it is around 800 million times the mass of the sun.</p>
<p>“Something is causing gas within the quasar to move around at very high speed, and the only phenomenon we know that achieves such speeds is orbit around a supermassive black hole,” Simcoe says.</p>
<p><strong>When the first stars turned on</strong></p>
<p>The newly identified quasar appears to inhabit a pivotal moment in the universe’s history. Immediately following the Big Bang, the universe resembled a cosmic soup of hot, extremely energetic particles. As the universe rapidly expanded, these particles cooled and coalesced into neutral hydrogen gas during an era that is sometimes referred to as the dark ages — a period bereft of any sources of light. Eventually, gravity condensed matter into the first stars and galaxies, which in turn produced light in the form of photons. As more stars turned on throughout the universe, their photons reacted with neutral hydrogen, ionizing the gas and setting off what’s known as the epoch of re-ionization.&nbsp;</p>
<p>Simcoe, Bañados, and their colleagues believe the newly discovered quasar existed during this fundamental transition, just at the time when the universe was undergoing a drastic shift in its most abundant element.</p>
<p>The researchers used FIRE to determine that a large fraction of the hydrogen surrounding the quasar is neutral. They extrapolated from that to estimate that the universe as a whole was likely about half neutral and half ionized at the time they observed the quasar. From this, they inferred that stars must have begun turning on during this time, 690 million years after the Big Bang.</p>
<p>“This adds to our understanding of our universe at large because we’ve identified that moment of time when the universe is in the middle of this very rapid transition from neutral to ionized,” Simcoe says. “We now have the most accurate measurements to date of when the first stars were turning on.”</p>
<p>There is one large mystery that remains to be solved: How did a black hole of such massive proportions form so early in the universe’s history? It’s thought that black holes grow by accreting, or absorbing mass from the surrounding environment. Extremely large black holes, such as the one identified by Simcoe and his colleagues, should form over periods much longer than 690 million years.</p>
<p>“If you start with a seed like a big star, and let it grow at the maximum possible rate, and start at the moment of the Big Bang, you could never make something with 800 million solar masses — it’s unrealistic,” Simcoe says. “So there must be another way that it formed. And how exactly that happens, nobody knows.”</p>
<p>This research was supported, in part, by the National Science Foundation (NSF), with support from construction of FIRE from NSF and from Curtis and Kathleen Marble.</p>
Artist’s conceptions of the most-distant supermassive black hole ever discovered, which is part of a quasar from just 690 million years after the Big Bang. It is surrounded by neutral hydrogen, indicating that it is from the period called the epoch of reionization, when the universe's first light sources turned on.
Image: Robin Dienel (Courtesy of the Carnegie Institution for Science)Astrophysics, Black holes, Kavli Institute, Physics, Research, School of Science, Space, astronomy and planetary science, National Science Foundation (NSF)Study sheds light on turbulence in astrophysical plasmashttps://news.mit.edu/2017/study-uncovers-new-mechanisms-astrophysical-plasma-turbulence-1201
Theoretical analysis uncovers new mechanisms in plasma turbulence.Fri, 01 Dec 2017 00:00:00 -0500David L. Chandler | MIT News Officehttps://news.mit.edu/2017/study-uncovers-new-mechanisms-astrophysical-plasma-turbulence-1201<p>Plasmas, gas-like collections of ions and electrons, make up an estimated 99 percent of the visible matter in the universe, including the sun, the stars, and the gaseous medium that permeates the space in between. Most of these plasmas, including the solar wind that constantly flows out from the sun and sweeps through the solar system, exist in a turbulent state. How this turbulence works remains a mystery; it’s one of the most dynamic research areas in plasma physics.</p>
<p>Now, two researchers have proposed a new model to explain these dynamic turbulent processes.</p>
<p>The findings, by Nuno Loureiro, an associate professor of nuclear science and engineering and of physics at MIT, and Stanislav Boldyrev, a professor of physics at the University of Wisconsin at Madison, are reported today in the <em>Astrophysical Journal</em>. The paper is the third in a series this year explaining key aspects of how these turbulent collections of charged particles behave.</p>
<p>“Naturally occurring plasmas in space and astrophysical environments are threaded by magnetic fields and exist in a turbulent state,” Loureiro says. “That is, their structure is highly disordered at all scales: If you zoom in to look more and more closely at the wisps and eddies that make up these materials, you’ll see similar signs of disordered structure at every size level.” And while turbulence is a common and widely studied phenomenon that occurs in all kinds of fluids, the turbulence that happens in plasmas is more difficult to predict because of the added factors of electrical currents and magnetic fields.</p>
<p>“Magnetized plasma turbulence is fascinatingly complex and remarkably challenging,” he says.</p>
<p><img alt="" src="/sites/mit.edu.newsoffice/files/MIT-Plasma-Reconnection.gif" style="width: 595px; height: 355px;" /></p>
<p><em>Simulation conducted by MIT student Daniel Groselj.</em></p>
<p>Magnetic reconnection is a complicated phenomenon that Loureiro has been studying in detail for more than a decade. To explain the process, he gives a well-studied example: “If you watch a video of a solar flare” as it arches outward and then collapses back onto the sun’s surface, “that’s magnetic reconnection in action. It’s something that happens on the surface of the sun that leads to explosive releases of energy.” Loureiro’s understanding of this process of magnetic reconnection has provided the basis for the new analysis that can now explain some aspects of turbulence in plasmas.</p>
<p>Loureiro and Boldyrev found that magnetic reconnection must play a crucial role in the dynamics of plasma turbulence, an insight that they say fundamentally changes the understanding of the dynamics and properties of space and astrophysical plasmas and “is indeed a conceptual shift in how one thinks about turbulence,” Loureiro says.</p>
<p>Existing hypotheses about the dynamics of plasma turbulence “can correctly predict some aspects of what is observed,” he says, but they “lead to inconsistencies.”</p>
<p>Loureiro worked with Boldyrev, a leading theorist on plasma turbulence, and the two realized “we can fix this by essentially merging the existing theoretical descriptions of turbulence and magnetic reconnection,” Loureiro explains. As a result, “the picture of turbulence gets conceptually modified and leads to results that more closely match what has been observed by satellites that monitor the solar wind, and many numerical simulations.”</p>
<p>Loureiro hastens to add that these results do not prove that the model is correct, but show that it is consistent with existing data. “Further research is definitely needed,” Loureiro says. “The theory makes specific, testable predictions, but these are difficult to check with current simulations and observations.”</p>
<p>He adds, “The theory is quite universal, which increases the possibilities for direct tests.” For example, there is some hope that a new NASA mission, the Parker Solar Probe, which is planned for launch next year and will be observing the sun’s corona (the hot ring of plasma around the sun that is only visible from Earth during a total eclipse), could provide the needed evidence. That probe, Loureiro says, will be going closer to the sun than any previous spacecraft, and it should provide the most accurate data on turbulence in the corona so far.</p>
<p>Collecting this information is well worth the effort, Loureiro says: “Turbulence plays a critical role in a variety of astrophysical phenomena,” including the flows of matter in the core of planets and stars that generate magnetic fields via a dynamo effect, the transport of material in accretion disks around massive central objects such as black holes, the heating of stellar coronae and winds (the gases constantly blown away from the surfaces of stars), and the generation of structures in the interstellar medium that fills the vast spaces between the stars. “A solid understanding of how turbulence works in a plasma is key to solving these longstanding problems,” he says.</p>
<p>“This important study represents a significant step forward toward a deeper physical&nbsp;understanding of magnetized&nbsp;plasma turbulence,” says Dmitri Uzdensky, an associate professor of physics at the University of Colorado, who was not involved in this work. “By&nbsp;elucidating deep connections and interactions between two ubiquitous and&nbsp;fundamental plasma processes — magnetohydrodynamic turbulence and magnetic reconnection — this analysis&nbsp;changes our theoretical picture of how the&nbsp;energy of turbulent plasma motions cascades from large down to small scales.”</p>
<p>He adds, “This work&nbsp;builds on a previous pioneering study published&nbsp;by these authors&nbsp;earlier this year and extends it into a&nbsp;broader&nbsp;realm of collisionless plasmas. This makes the&nbsp;resulting theory&nbsp;directly&nbsp;applicable to more realistic&nbsp;plasma&nbsp;environments found in nature. At the same time, this paper leads to&nbsp;new&nbsp;tantalizing&nbsp;questions about&nbsp;plasma&nbsp;turbulence and reconnection&nbsp;and thus opens new directions of research, hence&nbsp;stimulating future research efforts in space physics and plasma astrophysics.”</p>
<p>The research was supported by a CAREER award from the National Science Foundation and the U.S. Department of Energy through the Partnership in Basic Plasma Science and Engineering.</p>
Magnetic reconnection is a complicated phenomenon that Nuno Loureiro, an associate professor of nuclear science and engineering and of physics at MIT, has been studying in detail for more than a decade. To explain the process, he gives a well-studied example: “If you watch a video of a solar flare” as it arches outward and then collapses back onto the sun’s surface, “that’s magnetic reconnection in action. It’s something that happens on the surface of the sun that leads to explosive releases of energy.” Loureiro’s understanding of this process of magnetic reconnection has provided the basis for the new analysis that can now explain some aspects of turbulence in plasmas.
Image: NASANuclear science and engineering, Plasma Science and Fusion Center, Astrophysics, Fusion, Nuclear power and reactors, Planetary science, Space, astronomy and planetary science, School of EngineeringMonitoring activity in the geosynchronous belthttps://news.mit.edu/2017/mit-lincoln-laboratory-sensorsat-will-monitor-activity-in-geosynchronous-belt-1129
New ORS-5 SensorSat satellite developed at the MIT Lincoln Laboratory is fulfilling a critical need for situational awareness in space.Wed, 29 Nov 2017 17:30:00 -0500Dorothy Ryan | Lincoln Laboratoryhttps://news.mit.edu/2017/mit-lincoln-laboratory-sensorsat-will-monitor-activity-in-geosynchronous-belt-1129<p>In the darkness of 2 a.m. on Aug.&nbsp;26, the sky over Cape Canaveral, Florida, lit up with the bright plume of a Minotaur rocket lifting off from its launch pad. Aboard the rocket, a satellite developed by MIT's Lincoln Laboratory for the U.S. Air Force's Operationally Responsive Space (ORS) Office awaited its deployment into low Earth orbit.</p>
<p>The ORS-5 SensorSat spacecraft is on a 3-year mission to continually scan the geosynchronous belt, which at about 36,000 kilometers above Earth is home to a great number of satellites indispensable to the national economy and security. Data collected by SensorSat will help the United States keep a protective eye on the movements of satellites and space debris in the belt. &nbsp;</p>
<p>"There was nothing like seeing the massive Minotaur IV blast our creation into orbit, and then getting those familiar telemetry messages to indicate that it's really up there and operating just as it did in thermal-vacuum testing," says Andrew Stimac, the SensorSat program manager and assistant leader of the Lincoln Laboratory's Integrated Systems and Concepts Group.</p>
<p>In the months that SensorSat has been in orbit, it has undergone a complete checkout process, opened the cover of its optical system, and collected the first imagery of objects in the geosynchronous belt. The quality of the initial images has demonstrated that SensorSat utilizes a highly capable optical system that is able to conduct its required mission.</p>
<p>The 226-pound SensorSat is small in comparison to current U.S. satellites that monitor activity in the geosynchronous belt. SensorSat's size and its optical system design, which&nbsp;uses a smaller aperture, make it a lower-cost, faster-built option for space surveillance missions than the large systems designed for missions of 10 years or more.</p>
<p>"SensorSat is essentially a simple design, but it is a highly sensitive instrument that is one-tenth the size and one-tenth the cost of today's large satellites," says&nbsp;Grant Stokes, head of the Lincoln Laboratory's Space Systems and Technology Division, which collaborated with the Engineering Division to develop and build the satellite.</p>
<p>Traditional large surveillance satellites are designed to collect data on objects known to be in the geosynchronous belt. The optical systems on those satellites are mounted on gimbals so that they can turn their focus toward the targeted objects. SensorSat works on a different concept: Its fixed optical system surveys each portion of the belt that is within its current field of view as the satellite orbits Earth.</p>
<p>SensorSat makes approximately 14 passes around Earth each day, providing up-to-date views of activity in the geosynchronous belt. Stokes compared SensorSat's surveillance process to that of airport radars that continuously rotate to visualize a local airspace. Because SensorSat is not aimed at specific known objects, a secondary benefit to its concept of operations is that it may see new objects that pose threats to satellites within the belt.</p>
<p>The adoption of SensorSat-like systems that can be cost-effectively built on short timelines could also make it practical for the United States to more frequently deploy&nbsp;new satellites to keep pace with evolving technology.</p>
<p>SensorSat development and testing were accomplished in just three years, a period about one-third of that needed to develop and field large surveillance satellites. The SensorSat engineering effort involved the design, fabrication, and testing of the satellite structure and cover mechanism, lens optomechanics, telescope baffle, charge-coupled device packaging, electrical cabling, and thermal control.</p>
<p>The assembly, integration, and testing were conducted in Lincoln Laboratory's cleanroom facilities and its Engineering Test Laboratory. According to Mark Bury, assistant leader of the Laboratory's Structural and Thermal-Fluids Engineering Group, the shock, vibration, attitude control system, and thermal-vacuum testing performed were critical in validating SensorSat against the expected launch and space conditions it would need to endure.</p>
<p>"Perhaps the most important events occurred during thermal-vacuum testing," Bury says. "The satellite is exposed to conditions similar to those on orbit, and we used that test to validate our thermal design. Even more important, the thermal-vacuum test enabled us to get significant runtime on the avionics and components within the spacecraft, emulating the communication cadence and data streams that we would eventually see on orbit."</p>
<p>On&nbsp;July 7, less than two months before launch, SensorSat was shipped to Florida for installation on Orbital ATK's Minotaur IV inside&nbsp;a large cleanroom facility at Astrotech Space Operations, locatedjust outside the Kennedy Space Center. A team from Lincoln Laboratory performed final assembly steps and prepared the satellite with the software uploads needed initially on orbit.</p>
<p>Joint operations were then conducted with Orbital ATK to complete the mechanical and electrical integration prior to encapsulation with the rocket fairing. The integrated assembly was then transported from Astrotech to the Cape Canaveral Air Force Station launch pad 46 in mid-August.</p>
<p>SensorSat, which resides directly above the equator, orbits at an inclination of zero degrees, an orientation that Stokes says&nbsp;required very precise deployment of the satellite. The Minotaur IV, modified from a 25-year-old Air Force rocket design and now operated by Orbital ATK, was up to the challenge, using two new rocket motors to provide the extra lift needed to reach the equatorial orbit.</p>
<p>SensorSat is now orbiting Earth and collecting data to fulfill its space surveillance mission.</p>
An engineer installs SensorSat, developed at Lincoln Laboratory, in the thermal-vacuum chamber used for testing the satellite's tolerance of conditions in space. Photo: Glen CooperLincoln Laboratory, Space, astronomy and planetary science, Aeronautical and astronautical engineering, SatellitesScientists detect comets outside our solar systemhttps://news.mit.edu/2017/scientists-detect-comets-outside-our-solar-system-1026
Team of professional and citizen scientists identifies tails of comets streaking past a distant star.Wed, 25 Oct 2017 23:59:59 -0400Jennifer Chu | MIT News Officehttps://news.mit.edu/2017/scientists-detect-comets-outside-our-solar-system-1026<p>Scientists from MIT and other institutions, working closely with amateur astronomers, have spotted the dusty tails of six exocomets — comets outside our solar system — orbiting a faint star 800 light years from Earth.</p>
<p>These cosmic balls of ice and dust, which were about the size of Halley’s Comet and traveled about 100,000 miles per hour before they ultimately vaporized, are some of the smallest objects yet found outside our own solar system.</p>
<p>The discovery marks the first time that an object as small as a comet has been detected using transit photometry, a technique by which astronomers observe a star’s light for telltale dips in intensity. Such dips signal potential transits, or crossings of planets or other objects in front of a star, which momentarily block a small fraction of its light. &nbsp;</p>
<p>In the case of this new detection, the researchers were able to pick out the comet’s tail, or trail of gas and dust, which blocked about one-tenth of 1 percent of the star’s light as the comet streaked by.&nbsp;</p>
<p>“It’s amazing that something several orders of magnitude smaller than the Earth can be detected just by the fact that it’s emitting a lot of debris,” says Saul Rappaport, professor emeritus of physics in MIT’s Kavli Institute for Astrophysics and Space Research. “It’s pretty impressive to be able to see something so small, so far away.”</p>
<p>Rappaport and his team have published their results this week in the <em>Monthly Notices of the Royal Astronomical Society. </em>The paper’s co-authors are Andrew Vanderburg of the Harvard-Smithsonian Center for Astrophysics; several amateur astronomers including Thomas Jacobs of Bellevue, Washington; and researchers from the University of Texas at Austin, NASA’s Ames Research Center, and Northeastern University.</p>
<p><strong>“Where few have traveled”</strong></p>
<p>The detection was made using data from NASA’s Kepler Space Telescope, a stellar observatory that was launched into space in 2009. For four years, the spacecraft monitored about 200,000 stars for dips in starlight caused by transiting exoplanets.</p>
<p>To date, the mission has identified and confirmed more than 2,400 exoplanets, mostly orbiting stars in the constellation Cygnus, with the help of &nbsp;automated algorithms that quickly sift through Kepler’s data, looking for characteristic dips in starlight.</p>
<p>The smallest exoplanets detected thus far measure about one-third the size of the Earth. Comets, in comparison, span just several football fields, or a small city at their largest, making them incredibly difficult to spot.</p>
<p>However, on March 18, Jacobs, an amateur astronomer who has made it his hobby to comb through Kepler’s data, was able to pick out several curious light patterns amid the noise.</p>
<p>Jacobs, who works as an employment consultant for people with intellectual disabilities by day, is a member of the Planet Hunters — a citizen scientist project first established by Yale University to enlist amateur astronomers in the search for exoplanets. Members were given access to Kepler’s data in hopes that they might spot something of interest that a computer might miss.</p>
<p>In January, Jacobs set out to scan the entire four years of Kepler’s data taken during the main mission, comprising over 200,000 stars, each with individual light curves, or graphs of light intensity tracked over time. Jacobs spent five months sifting by eye through the data, often before and after his day job, and through the weekends.</p>
<p>“Looking for objects of interest in the Kepler data requires patience, persistence, and perseverance,” Jacobs says. “For me it is a form of treasure hunting, knowing that there is an interesting event waiting to be discovered. It is all about exploration and being on the hunt where few have traveled before.”</p>
<p><strong>“Something we’ve seen before”</strong></p>
<p>Jacobs’ goal was to look for anything out of the ordinary that computer algorithms may have passed over. In particular, he was searching for single transits — dips in starlight that happen only once, meaning they are not periodic like planets orbiting a star multiple times.</p>
<p>In his search, he spotted three such single transits around KIC 3542116, a faint star located 800 light years from Earth (the other three transits were found later by the team). He flagged the events and alerted Rappaport and Vanderburg, with whom he had collaborated in the past to interpret his findings.</p>
<p>“We sat on this for a month, because we didn’t know what it was — planet transits don’t look like this,” Rappaport recalls. “Then it occurred to me that, ‘Hey, these look like something we’ve seen before.’”</p>
<p>In a typical planetary transit, the resulting light curve resembles a “U,” with a sharp dip, then an equally sharp rise, as a result of a planet first blocking a little, then a lot, then a little of the light as it moves across the star. However, the light curves that Jacobs identified appeared asymmetric, with a sharp dip, followed by a more gradual rise.</p>
<p>Rappaport realized that the asymmetry in the light curves resembled disintegrating planets, with long trails of debris that would continue to block a bit of light as the planet moves away from the star. However, such disintegrating planets orbit their star, transiting repeatedly. In contrast, Jacobs had observed no such periodic pattern in the transits he identified.</p>
<p>“We thought, the only kind of body that could do the same thing and not repeat is one that probably gets destroyed in the end,” Rappaport says.</p>
<p>In other words, instead of orbiting around and around the star, the objects must have transited, then ultimately flown too close to the star, and vaporized.</p>
<p>“The only thing that fits the bill, and has a small enough mass to get destroyed, is a comet,” Rappaport says.</p>
<p>The researchers calculated that each comet blocked about one-tenth of 1 percent of the star’s light. To do this for several months before disappearing, the comet likely disintegrated entirely, creating a dust trail thick enough to block out that amount of starlight.</p>
<p>Vanderburg says the fact that these six exocomets appear to have transited very close to their star in the past four years raises some intriguing questions, the answers to which could reveal some truths about our own solar system.</p>
<p>“Why are there so many comets in the inner parts of these solar systems?” Vanderburg says. “Is this an extreme bombardment era in these systems? That was a really important part of our own solar system formation and may have brought water to Earth. Maybe studying exocomets and figuring out why they are found around this type of star … could give us some insight into how bombardment happens in other solar systems.”</p>
<p>The researchers say that in the future, the MIT-led Transiting Exoplanet Survey Satellite (TESS) mission will continue the type of research done by Kepler.</p>
<p>Apart from contributing to the fields of astrophysics and astronomy, Rappaport says, the new detection speaks to the perserverence and discernment of citizen scientists.</p>
<p>“I could name 10 types of things these people have found in the Kepler data that algorithms could not find, because of the pattern-recognition capability in the human eye,” Rappaport says. “You could now write a computer algorithm to find this kind of comet shape. But they were missed in earlier searches. They were deep enough but didn’t have the right shape that was programmed into algorithms. I think it’s fair to say this would never have been found by any algorithm.”</p>
<p>This research made use of data collected by the Kepler mission, funded by the NASA Science Mission directorate.</p>
An artist’s conception of a view from within the Exocomet system KIC 3542116.Image: Danielle FutselaarAstronomy, Astrophysics, Kavli Institute, NASA, Physics, Research, Satellites, School of Science, space, Space, astronomy and planetary scienceMIT researchers discuss the new &quot;multi-messenger&quot; era of astrophysics researchhttps://news.mit.edu/2017/mit-researchers-discuss-LIGO-event-astrophysics-research-1018
Mavalvala, Evans, Frebel, Katsavounidis, and Vitale discuss the science behind LIGO&#039;s observations of a neutron star collision.Wed, 18 Oct 2017 16:50:01 -0400Julia C. Keller | School of Sciencehttps://news.mit.edu/2017/mit-researchers-discuss-LIGO-event-astrophysics-research-1018<p>On Monday, Oct.&nbsp;16, scientists from the National Science Foundation (NSF), representatives from the Laser Interferometer Gravitational-Wave Observatory (LIGO) Scientific Collaboration, and other researchers from ground-based&nbsp;and space-based observatories around the world announced the detection of GW170817 — gravitational waves resulting from the merger of two neutron stars.</p>
<p>This detection was the first correlation between gravitational waves and electromagnetic signals in the form of gamma ray bursts and X-ray, ultraviolet, optical, infrared, and radio waves.</p>
<p>Following the <a href="http://www.youtube.com/c/VideosatNSF/live" target="_blank">live webcast</a> of the announcement made from the National Press Club in Washington,&nbsp;MIT President L. Rafael Reif opened the remarks for an on-campus panel.</p>
<p>“Today is a wonderful reminder that investing in basic science is investing in our nation’s future,”&nbsp;he&nbsp;told the crowd&nbsp;in the Vannevar Bush Room.&nbsp;</p>
<p>Reif then acknowledged the vision of luminaries like&nbsp;Bush, the former MIT dean of engineering, who helped establish what would later become the NSF, the funding agency that has&nbsp;supported the development of the LIGO and Advanced LIGO projects over many decades.</p>
<p>“Bush and his colleagues understood that that basic science can be electrifying, revolutionary, and catalytic. But they also knew that the work that produces fundamental breakthroughs is painstaking, rigorous, and slow,” he said. “For that reason, basic science requires the deep, steady support that only government can provide.”</p>
<p>Reif then introduced Nergis Mavalvala, the Curtis and Kathleen Marble Professor of Astrophysics —&nbsp;“a LIGO pioneer in her own right” — who began her career as a graduate student of MIT Professor Emeritus Rainer Weiss, the winner of the 2017 Nobel Prize in physics for his work on LIGO.&nbsp;</p>
<p>Mavalvala led a panel of MIT scientists in a discussion of the science of the discovery and of its importance in opening up a new field of astronomical discovery.</p>
<p><strong>Multi-messenger&nbsp;astronomy</strong></p>
<p>“I’d always believed that gravitational waves would reveal more of the universe to us — that there would be many more discoveries. But I have to say that I didn’t imagine that it would be quite so soon and certainly not as spectacular,” said Mavalvala. “The combination of gravitational waves and electromagnetic observation, the show that we’ve put together of sound and light, has really blown away most of us in the field.”&nbsp;</p>
<p>The inspiraling of the neutron stars produced gravitational waves that were detected for more than a minute with the LIGO detectors, and the additional “messengers” from the event, in the form of visible light and X-ray and radio waves, lasted for days after the cataclysmic event.</p>
<p>The neutron star merger occurred as part of the constellation we know as Hydra in the galaxy NGC4993, only 130 million light years away as compared with LIGO and Virgo’s most recent black hole merger detection nearly 1.8 billion light years away.<br />
&nbsp;<br />
Mavalvala said the researchers had heard scientists at the DC press event say that the event happened&nbsp;in “a galaxy far away,’” but by astronomers’ standards, it&nbsp;actually happened in a galaxy “near away.”</p>
<p><strong>We are made of “neutron star stuff”</strong></p>
<p>The astronomical event also confirmed the theory that the collision of these super dense neutron stars produced elements heavier than iron in the periodic table. Mavalvala first asked Anna Frebel, the Silverman (1968) Family Career Development Associate Professor of Physics, to speak about the neutron start collision as the “factories where these heavy elements are produced.”</p>
<p>Frebel began with the famous quote from Carl Sagan: “We are made from star stuff.”&nbsp;</p>
<p>“After today, we know a lot more about what that ‘star stuff actually’ is and how it’s made,” said Frebel, who is not on the LIGO or Virgo teams. “We can confidently add ‘and neutron star stuff’” to the list of what humans are made from, she said.</p>
<p>To create elements heavier than iron, neutrons must bombard something like an iron nucleus that would ultimately decay and form a stable element like silver or gold. “When you have two neutron stars colliding, you have neutrons galore,” said Frebel. “We had indication before [this event detection] that only neutron star merger can produce these elements. No other site has enough ‘oopmf.’”</p>
<p>The importance of this merger event, said Frebel, is that “we can actually see element formation in action.”</p>
<p>In the decay of these neutron-rich isotopes to stable elements, light is emitted and can be can be observed with light-collecting telescopes as a “‘kilonova’, this afterglow of element production,” she said. Though the creation of the isotopes only takes one or two seconds, Frebel said, the decay to stable elements take a couple weeks to occur. Scientists therefore have a long window to be able to make observations of this event.&nbsp;</p>
<p>Erik Katsavounidis, a senior research scientist in MIT’s Kavli Institute for Astrophysics and Space Research, added that the event “is not just a gold&nbsp;mine scientifically, but it’s literally a gold mine that we’ve just discovered.”&nbsp;</p>
<p>Katsavounidis then responded to a question about whether the event shed new insight into the rate of formation of these neutron star mergers given the amount of heavy elements, such as gold and platinum, present in the Earth’s crust.&nbsp;</p>
<p>Though it was known that supernovae could produce heavier elements, said Katsavounidis, astrophysicists theorized that only a kilonova produced by a binary neutron star merger could produce the abundance of those elements in our solar system.&nbsp;</p>
<p>Salvatore Vitale, an assistant professor of physics, continued the discussion by commenting on the rate of discovery of these events.&nbsp;</p>
<p>“Once LIGO is at its full design sensitivity,” said Vitale, “it would be on the order of 40 to 50 neutron stars per year.”</p>
<p>“We have about a factor of 2 to go from the current sensitivity and the design and that corresponds to roughly a factor of 10 in terms of the rate,” said Matthew Evans, the D. Reid Weedon, Jr. '41 Career Development Professor of Physics and an expert in the design of the interferometers.&nbsp;</p>
<p>“It’s not strange that we saw one of these with our current sensitivity,” said Evans, “But as we go forward with the design, we’ll have several per year.”&nbsp;</p>
<p>Katsavounidis clarified that the rate of detecting an event similar to GW170817 is still unknown because it’s not a given that a neutron star merger would necessarily be accompanied by electromagnetic radiation as seen in this most recent event.</p>
<p>In addition to shedding light on the formation of heavy elements and the rate at which scientists predict these types of events might occur, Mavalvala later added that the detection solves a “decades-long mystery” of the origin of short-duration gamma ray bursts. The Fermi Gamma-ray Space telescope recorded a gamma ray burst on Aug. 17, performing just as intended and as it does with bursts that occur more than 200 times a year. The difference was the near-simultaneous gravitational-wave detection from the LIGO-Virgo global network of interferometers that linked the two events.</p>
<p>When asked about how more than 70 space research labs and telescopes could have so quickly coordinated to observe this event, Katsavounidis said that a coordinated effort was put into place beginning more than 10 years ago for rapid analysis, coordination, and communication.&nbsp;</p>
<p>He then showed a slide of how the event unfolded over time from first the gravitational wave signal lasting just over a minute to electromagnetic radiation that could be observed for days to weeks after the event.</p>
<p>“[It’s like] you’re staring at Van Gogh’s Starry Night and there are 11 swirly stars,” said Katsavounidis. “And you’re listening to Benny Goodman do the glissando at the opening [of Gershwin ‘Rhapsody in Blue’] and then you see the 12th swirly star.”&nbsp;</p>
<p>As to whether the final object in the sky is, in fact, another neutron star or a black hole is currently a puzzle for astronomers to work out. “[The answer] depends on how squishy the neutron stars are and how much mass they can support before they collapse into a black hole,” said Vitale. “That’s one of the things we don’t know yet."</p>
Members of MIT's panel on the LIGO observation of a merger of neutron stars, (left to right) Anna Frebel, Salvatore Vitale, Nergis Mavalvala, Erik Katsavounidis, and Matthew Evans, pose for a photo at the Oct. 16 event.Photo: Jake BelcherSchool of Science, Astronomy, Astrophysics, Kavli Institute, Stars, Space, astronomy and planetary science, National Science Foundation (NSF), LIGO, Chemistry, Special events and guest speakers, PhysicsGood Housekeeping honors rocket scientist Tiera Guinn &#039;17https://news.mit.edu/2017/good-housekeeping-honors-mit-rocket-scientist-tiera-guinn-1016
Design engineer and 2017 alumna working on the largest rocket ever created by NASA was named an &quot;Awesome Woman of 2017.&quot;Mon, 16 Oct 2017 13:00:01 -0400Jay London | MIT Alumni Associationhttps://news.mit.edu/2017/good-housekeeping-honors-mit-rocket-scientist-tiera-guinn-1016<p>An MIT alumna has won a <em>Good Housekeeping</em> <a href="http://www.goodhousekeeping.com/life/inspirational-stories/a45437/awesome-women-awards-tiera-guinn/">Awesome Women Award</a>, which honors women who are, magazine says, “redefining race, fighting poverty, reinventing fashion, literally saving lives, and more.” Tiera Guinn ’17, a design engineer at Boeing who is building a spacecraft&nbsp;to put humans on Mars, is one of 10 honorees.</p>
<p>“Some kids dream of being princesses, but Tiera Guinn wanted to build rockets,” Guinn's profile in the magazine states. “In June 2016, she realized that dream when Boeing hired her to design and analyze the hardware for the largest NASA rocket ever created — one that’s meant to take humans to Mars — before her recent graduation from MIT.”</p>
<p>Guinn told the magazine that it is “humbling to be a part of this moment in history.”</p>
<p>The article cites Guinn's&nbsp;passion for space exploration and her advocacy for diversity in STEM, which dates back to her time at MIT where she majored in aeronautics and astronautics. As co-chair of MIT’s&nbsp;<a href="http://bwa.mit.edu/index.html" target="_blank">Black Women’s Alliance</a>, she introduced astronaut Yvonne Cagle at an MIT community-wide talk,&nbsp;“<a href="http://news.mit.edu/2015/mission-space-for-all-yvonne-cagle-0521" target="_self">Women in Space</a>,” in May 2015.</p>
<p>The <em>Good Housekeeping</em> award is&nbsp;not the first time Guinn has been recognized for her work. Already this year, she’s been featured in <a href="http://www.essence.com/culture/22-year-old-mit-student-space-engineer"><em>Essence</em> magazine</a>, the <a href="http://www.huffingtonpost.com/entry/this-22-year-old-is-already-an-engineer-at-nasa_us_5894c59be4b0c1284f25c913"><em>The Huffington Post</em></a>, and <em><a href="http://college.usatoday.com/2017/02/13/this-college-senior-juggles-school-and-a-job-with-nasa-like-its-no-big-deal/">USA Today</a>,&nbsp;</em>where she has shared her hopes for the future of STEM education and the story of how&nbsp;she first fell in love with math at the grocery store.</p>
<p>In a February story,&nbsp;<em>Huffington Post <a href="http://www.huffingtonpost.com/entry/this-22-year-old-is-already-an-engineer-at-nasa_us_5894c59be4b0c1284f25c913">Black Voices</a></em>&nbsp;said&nbsp;Guinn&nbsp;“will soon be graduating from MIT with a 5.0 GPA and is clearly on a path to success. She said she’d advise young girls looking to follow in her footsteps to expect obstacles throughout their journey.”</p>
<p>“You have to look forward to your dream and you can’t let anybody get in the way of it,”&nbsp;Guinn is quoted as saying. “No matter how tough it may be, no matter how many tears you might cry, you have to keep pushing. And you have to understand that nothing comes easy. Keeping your eyes on the prize, you can succeed.”</p>
Tiera Guinn ’17 has been named an "Awesome Woman of 2017" by Good Housekeeping magazine. Image courtesy of Good Housekeeping.School of Engineering, Aeronautical and astronautical engineering, Alumni/ae, NASA, Women in STEM3Q: Scott Hughes on cosmic distances and the future of gravitational wave astronomyhttps://news.mit.edu/2017/3q-scott-hughes-cosmic-distances-and-future-of-gravitational-wave-astronomy-1016
Professor of physics describes our understanding of the expansion of the universe through “standard sirens.”Mon, 16 Oct 2017 12:00:35 -0400Julia C. Keller | School of Sciencehttps://news.mit.edu/2017/3q-scott-hughes-cosmic-distances-and-future-of-gravitational-wave-astronomy-1016<p><em>On Monday, Oct. 16, National Science Foundation Director France Córdova, MIT senior research scientist and LIGO Scientific Collaboration spokesperson David Shoemaker, and other representatives from Caltech and the Virgo detector, announced the <a href="http://news.mit.edu/2017/ligo-virgo-first-detection-gravitational-waves-colliding-neutron-stars-1016" target="_self">detection of GW170817</a> — the merger of two neutron stars as observed by the two Laser Interferometer Gravitational-wave Observatory (LIGO) detectors, located in Livingston, Louisiana, and Hanford, Washington.</em></p>
<p><em>Unlike the four <a href="http://news.mit.edu/2017/gravitational-waves-binary-black-hole-merger-observed-ligo-and-virgo-0927" target="_self">binary black hole systems previously detected</a>, the observation of a neutron-neutron star merger opens up a new chapter in the science of gravitational waves: the first correlation between gravitational waves (GWs) and an electromagnetic signal, in this case short-hard gamma ray bursts (SHBs).</em></p>
<p><em>In research preceding the LIGO detector systems’ first and second observing runs, Scott Hughes, MIT professor in the Department of Physics, working with Daniel Holz of the University of Chicago, developed a theoretical technique by which measuring the gravitational waves and SHBs of this kind of binary system could be used to measure cosmic distances, and to learn about the universe’s expansion.</em></p>
<p><em>Hughes, who is not a member of the LIGO collaboration, answers questions about this technique and the future of gravitational wave astronomy.</em></p>
<p><strong>Q: </strong>What are “standard candles” in astronomy and how does the “standard siren” technique allow us to measure cosmic distances with greater certainty than other methods?</p>
<p><strong>A:</strong> Measuring distances is one of the hardest problems in astronomy. What kind of yardstick can we use to measure distances so large that light takes millions or billions of years to travel across?</p>
<p>Imagine a gigantic lightbulb that puts out 400 trillion trillion watts — that’s the luminosity of our sun. The energy we receive from this lightbulb falls off as the distance squared between us and the bulb. Such a lightbulb 2 light years away would be four times dimmer than if it were 1 light year away. This source is a standard candle: an astronomical object whose luminosity is known so well that we can infer how far away it is from the brightness we measure.</p>
<p>Although nature doesn’t provide us with such standard lightbulbs, astronomers have found that certain objects have luminosities that can be calibrated so that they are effectively standardized. Key to standardizing these objects are a series of measurements called the “cosmic distance ladder.” This uses a technique called parallax, which examines how the relative position of nearby stars on the sky changes as the Earth moves in its orbit. Using parallax, astronomers have learned that a class of stars called Cepheid variables — thousands of times more luminous than our sun — are very good standard candles. They can find these candles in distant galaxies, and use them to determine how far away those galaxies are.</p>
<p>In 1986, Bernard Schutz of the University of Cardiff in Wales pointed out that binary coalescence — such as the merger of two neutron stars — is a self calibrating standard candle: Measuring its waves makes it possible to directly measure the binary’s distance without the cosmic distance ladder. Schutz’s key observation is that the rate at which the binary’s frequency changes is directly related to the system’s intrinsic gravitational wave “loudness.” (Gravitational waves have a sound-like character — recall the famous “chirp” from the first detection — and it is useful to think of strong events as loud, and weak events as quiet.)</p>
<p>Just as the observed brightness of a star depends on both its intrinsic luminosity and how far away it is, the strength of the gravitational waves that we measure depends on both their source’s intrinsic loudness and how far away it is. By observing the waves with detectors like LIGO and Virgo, we learn both the waves’ intrinsic loudness as well as their loudness at the Earth. This allows us to directly determine distance to the source.</p>
<p>About 12 years ago, Daniel Holz and I examined how well this idea could be implemented, focusing on how it could be done if the gravitational waves were accompanied by some electromagnetic signature, such as a short-hard gamma-ray burst. Given the sound-like character of gravitational waves, we named such an event a “standard siren.” Our analysis got us excited about how the self-calibrating nature of these events could make them powerful tools for important measurements in cosmology.</p>
<p><strong>Q:</strong> How does this observation provide a probe of the universe’s expansion and what could other potential observations — such as a black hole-neutron star merger — tell us about the origin of black holes or the expansion of our universe?</p>
<p><strong>A:</strong> Edwin Hubble first observed that our universe is expanding, finding that distant galaxies move away from us at a rate proportional to their distance. The wavelengths of light from such galaxies are shifted to the red part of the spectrum, a phenomenon in light akin to the Doppler effect in sound. Precise measurements of distance and redshift are needed in order to figure out how fast the expansion is proceeding. The binary inspiral of GW170817 measured its distance; telescope observations of the accompanying gamma-ray burst measured its redshift. Those are exactly the pieces of information needed to measure Hubble’s constant, which tells us how fast the universe is now expanding.</p>
<p>Any measurement of binary coalescence that is accompanied by an electromagnetic event, like a gamma-ray burst, can be used to measure the expansion of the universe exactly as was done with GW170817. Indeed, we hope for more events like this: Combining many distance-redshift measurements will make it possible to average out noise and other error effects, and improve our ability to measure Hubble’s constant.</p>
<p>Although Hubble’s constant had already been measured by a few different techniques, these techniques appear to be converging to two different values! It is unclear if this discrepancy is because of some currently unknown bit of cosmic physics, or if it is a systematic error in the measurements. Because the standard siren does not require a series of calibrations, it has tremendous promise for resolving this tension in the Hubble constant’s value.</p>
<p>In addition to telling us about the distance to the event, each of these measurements such as GW170817 provides a wealth of data about the masses and other properties of the objects involved. As we build up a catalog of data about things like black hole masses and spins and neutron star masses, we will gain more and deeper understanding of how these objects are distributed in the universe, shedding light on the nature of the matter that makes up neutron stars and how some of the heaviest elements were formed.</p>
<p><strong>Q:</strong> What might space-based gravitational wave and electromagnetic measurements tell us that ground-based measurements from LIGO or Virgo could not?</p>
<p><strong>A:</strong> This question is near to my heart, since I have spent a lot of my career thinking about measurements using the <a href="https://lisa.nasa.gov/" target="_blank">Laser Interferometer Space Antenna (LISA)</a> — the planned space-based gravitational-wave detector. Indeed, the primary focus of my first standard sirens paper with Holz was on sirens enabled by LISA measurements!</p>
<p>LISA will be sensitive to gravitational waves at much lower frequencies than LIGO and Virgo can measure. Low-frequency waves come from much more massive sources, like the coalescence of black holes millions of times more massive than the sun. Such sources may enable LISA to make standard siren measurements from sources that are tremendously far away — perhaps tens of billions of light years, from an epoch when the universe was relatively young.</p>
<p>The distant standard sirens that LISA may enable tell us about the expansion of the universe at a very different cosmic time than the relatively nearby sirens (a few hundred million light years away) that LIGO and Virgo measure. Together, these events would make it possible to precisely probe the expansion of the universe over a wide range of cosmic times, enabling a wholly new way of probing the large-scale geometry of our universe.</p>
Scott HughesPhoto: Department of PhysicsAstronomy, Astrophysics, Black holes, Kavli Institute, LIGO, Space, astronomy and planetary science, National Science Foundation (NSF), Research, Physics, School of Science, 3 Questions, FacultyLIGO and Virgo make first detection of gravitational waves produced by colliding neutron starshttps://news.mit.edu/2017/ligo-virgo-first-detection-gravitational-waves-colliding-neutron-stars-1016
Discovery marks first cosmic event observed in both gravitational waves and light.Mon, 16 Oct 2017 09:59:59 -0400Jennifer Chu | MIT News Officehttps://news.mit.edu/2017/ligo-virgo-first-detection-gravitational-waves-colliding-neutron-stars-1016<p>For the first time, scientists have directly detected gravitational waves — ripples in space-time — in addition to light from the spectacular collision of two neutron stars. This marks the first time that a cosmic event has been viewed in both gravitational waves and light.</p>
<p>The discovery was made using the U.S.-based Laser Interferometer Gravitational-Wave Observatory (LIGO); the Europe-based Virgo detector; and some 70 ground- and space-based observatories.</p>
<p>Neutron stars are the smallest, densest stars known to exist and are formed when massive stars explode in supernovas. As these neutron stars spiraled together, they emitted gravitational waves that were detectable for about 100 seconds; when they collided, a flash of light in the form of gamma rays was emitted and seen on Earth about two seconds after the gravitational waves. In the days and weeks following the smashup, other forms of light, or electromagnetic radiation — including X-ray, ultraviolet, optical, infrared, and radio waves — were detected.</p>
<p><iframe allowfullscreen="" frameborder="0" height="315" src="https://www.youtube.com/embed/sgkDoSbHHVU?rel=0" width="560"></iframe></p>
<p><span style="font-size:10px;"><em>Video: NASA's Goddard Space Flight Center/CI Lab</em></span></p>
<p>The observations have given astronomers an unprecedented opportunity to probe a collision of two neutron stars. For example, observations made by the U.S. Gemini Observatory, the European Very Large Telescope, and the Hubble Space Telescope reveal signatures of recently synthesized material, including gold and platinum, solving a decades-long mystery of where about half of all elements heavier than iron are produced.&nbsp;&nbsp;</p>
<p>The LIGO-Virgo results are published today in the journal <em>Physical Review Letters</em>; additional papers from the LIGO and Virgo collaborations and the astronomical community have been either submitted or accepted for publication in various journals.</p>
<p>“It is tremendously exciting to experience a rare event that transforms our understanding of the workings of the universe,” says France A. Córdova, director of the National Science Foundation (NSF), which funds LIGO.&nbsp;“This discovery realizes a long-standing goal many of us have had, that is, to simultaneously observe rare cosmic events using both traditional as well as gravitational-wave observatories. Only through NSF’s four-decade investment in gravitational-wave observatories, coupled with telescopes that observe from radio to gamma-ray wavelengths, are we able to expand our opportunities to detect new cosmic phenomena and piece together a fresh narrative of the physics of stars in their death throes.”</p>
<p><iframe allowfullscreen="" frameborder="0" height="315" src="https://www.youtube.com/embed/F7-FSPyjc94?rel=0" width="560"></iframe></p>
<p><span style="font-size:10px;"><em>Video: Georgia Tech</em></span></p>
<p><strong>A stellar sign</strong></p>
<p>The gravitational signal, named GW170817, was first detected on Aug. 17 at 8:41 a.m. Eastern Daylight Time; the detection was made by the two identical LIGO detectors, located in Hanford, Washington, and Livingston, Louisiana. The information provided by the third detector, Virgo, situated near Pisa, Italy, enabled an improvement in localizing the cosmic event. At the time, LIGO was nearing the end of its second observing run since being upgraded in a program called Advanced LIGO, while Virgo had begun its first run after recently completing an upgrade known as Advanced Virgo.</p>
<p>The NSF-funded LIGO observatories were conceived, constructed, and operated by Caltech and MIT. Virgo is funded by the Istituto Nazionale di Fisica Nucleare (INFN) in Italy and the Centre National de la Recherche Scientifique (CNRS) in France, and operated by the European Gravitational Observatory. Some 1,500 scientists in the LIGO Scientific Collaboration and the Virgo Collaboration work together to operate the detectors and to process and understand the gravitational-wave data they capture.</p>
<p>Each observatory consists of two long tunnels arranged in an L shape, at the joint of which a laser beam is split in two. Light is sent down the length of each tunnel, then reflected back in the direction it came from by a suspended mirror. In the absence of gravitational waves, the laser light in each tunnel should return to the location where the beams were split, at precisely the same time. If a gravitational wave passes through the observatory, it will alter each laser beam’s arrival time, creating an almost imperceptible change in the observatory’s output signal.</p>
<p>On Aug. 17, LIGO’s real-time data analysis software caught a strong signal of gravitational waves from space in one of the two LIGO detectors. At nearly the same time, the Gamma-ray Burst Monitor on NASA’s Fermi space telescope had detected a burst of gamma rays. LIGO-Virgo analysis software put the two signals together and saw it was highly unlikely to be a chance coincidence, and another automated LIGO analysis indicated that there was a coincident gravitational wave signal in the other LIGO detector. Rapid gravitational-wave detection by the LIGO-Virgo team, coupled with Fermi’s gamma-ray detection, enabled the launch of follow-up by telescopes around the world.</p>
<p>The LIGO data indicated that two astrophysical objects located at the relatively close distance of about 130 million light years from Earth had been spiraling in toward each other. It appeared that the objects were not as massive as binary black holes — objects that LIGO and Virgo have previously detected. Instead, the inspiraling objects were estimated to be in a range from around 1.1 to 1.6 times the mass of the sun, in the mass range of neutron stars. A neutron star is about 20 kilometers, or 12 miles, in diameter and is so dense that a teaspoon of neutron star material has a mass of about a billion tons.</p>
<p>While binary black holes produce “chirps” lasting a fraction of a second in the LIGO detector’s sensitive band, the Aug. 17 chirp lasted approximately 100 seconds and was seen through the entire frequency range of LIGO — about the same range as common musical instruments. Scientists could identify the chirp source as objects that were much less massive than the black holes seen to date.</p>
<p>“It immediately appeared to us the source was likely to be neutron stars, the other coveted source we were hoping to see — and promising the world we would see,” says David Shoemaker, spokesperson for the LIGO Scientific Collaboration and senior research scientist in MIT’s Kavli Institute for Astrophysics and Space Research. “From informing detailed models of the inner workings of neutron stars and the emissions they produce, to more fundamental physics such as general relativity, this event is just so rich. It is a gift that will keep on giving.”</p>
<p>“Our background analysis showed an event of this strength happens less than once in 80,000 years by random coincidence, so we recognized this right away as a very confident detection and a remarkably nearby source,” adds Laura Cadonati, professor of physics at Georgia Tech and deputy spokesperson for the LIGO Scientific Collaboration. “This detection has genuinely opened the doors to a new way of doing astrophysics. I expect it will be remembered as one of the most studied astrophysical events in history.”</p>
<p>Theorists have predicted that when neutron stars collide, they should give off gravitational waves and gamma rays, along with powerful jets that emit light across the electromagnetic spectrum. The gamma-ray burst detected by Fermi, and soon thereafter confirmed by the European Space Agency’s gamma-ray observatory INTEGRAL, is what’s called a short gamma-ray burst; the new observations confirm that at least some short gamma-ray bursts are generated by the merging of neutron stars — something that was only theorized before.</p>
<p>“For decades we’ve suspected short gamma-ray bursts were powered by neutron star mergers,” says Fermi Project Scientist Julie McEnery of NASA’s Goddard Space Flight Center. “Now, with the incredible data from LIGO and Virgo for this event, we have the answer. The gravitational waves tell us that the merging objects had masses consistent with neutron stars, and the flash of gamma rays tells us that the objects are unlikely to be black holes, since a collision of black holes is not expected to give off light."</p>
<p>But while one mystery appears to be solved, new mysteries have emerged. The observed short gamma-ray burst was one of the closest to Earth seen so far, yet it was surprisingly weak for its distance. Scientists are beginning to propose models for why this might be, McEnery says, adding that new insights are likely to arise for years to come.</p>
<p><strong>A patch in the sky</strong></p>
<p>Though the LIGO detectors first picked up the gravitational wave in the United States, Virgo, in Italy, played a key role in the story. Due to its orientation with respect to the source at the time of detection, Virgo recovered a small signal; combined with the signal sizes and timing in the LIGO detectors, this allowed scientists&nbsp;to precisely triangulate the position in the sky. After performing a thorough vetting to make sure the signals were not an artifact of instrumentation, scientists concluded that a gravitational wave came from a relatively small patch in the southern sky.</p>
<p>“This event has the most precise sky localization of all detected gravitational waves so far,” says Jo van den Brand of Nikhef (the Dutch National Institute for Subatomic Physics) and VU University Amsterdam, who is the spokesperson for the Virgo collaboration. “This record precision enabled astronomers to perform follow-up observations that led to a plethora of breathtaking results.”</p>
<p>“This result is a great example of the effectiveness of teamwork, of the importance of coordinating, and of the value of scientific collaboration,” adds EGO Director Federico Ferrini. “We are delighted to have played our relevant part in this extraordinary scientific challenge: Without Virgo, it would have been very difficult to locate the source of the gravitational waves.”</p>
<p>Fermi was able to provide a localization that was later confirmed and greatly refined with the coordinates provided by the combined LIGO-Virgo detection. With these coordinates, a handful of observatories around the world were able, hours later, to start searching the region of the sky where the signal was thought to originate. A new point of light, resembling a new star, was first found by optical telescopes. Ultimately, about 70 observatories on the ground and in space observed the event at their representative wavelengths.</p>
<p>“This detection opens the window of a long-awaited ‘multimessenger’ astronomy,” says Caltech’s David H. Reitze, executive director of the LIGO Laboratory. “It’s the first time that we’ve observed a cataclysmic astrophysical event in both gravitational waves and electromagnetic waves — our cosmic messengers. Gravitational-wave astronomy offers new opportunities to understand the properties of neutron stars in ways that just can’t be achieved with electromagnetic astronomy alone.”</p>
<p><strong>A fireball and an afterglow</strong></p>
<p>Each electromagnetic observatory will be releasing its own detailed observations of the astrophysical event. In the meantime, a general picture is emerging among all observatories involved that further confirms that the initial gravitational-wave signal indeed came from a pair of inspiraling neutron stars.</p>
<p>Approximately 130 million years ago, the two neutron stars were in their final moments of orbiting each other, separated only by about 300 kilometers, or 200 miles, and gathering speed while closing the distance between them. As the stars spiraled faster and closer together, they stretched and distorted the surrounding space-time, giving off energy in the form of powerful gravitational waves, before smashing into each other.</p>
<p>At the moment of collision, the bulk of the two neutron stars merged into one ultradense object, emitting a “fireball” of gamma rays. The initial gamma-ray measurements, combined with the gravitational-wave detection, also provide confirmation for Einstein’s general theory of relativity, which predicts that gravitational waves should travel at the speed of light.</p>
<p>Theorists have predicted that what follows the initial fireball is a “kilonova” — a phenomenon by which the material that is left over from the neutron star collision, which glows with light, is blown out of the immediate region and far out into space. The new light-based observations show that heavy elements, such as lead and gold, are created in these collisions and subsequently distributed throughout the universe.</p>
<p>In the weeks and months ahead, telescopes around the world will continue to observe the afterglow of the neutron star merger and gather further evidence about various stages of the merger, its interaction with its surroundings, and the processes that produce the heaviest elements in the universe.</p>
<p>“When we were first planning LIGO back in the late 1980s, we knew that we would ultimately need an international network of gravitational-wave observatories, including Europe, to help localize the gravitational-wave sources so that light-based telescopes can follow up and study the glow of events like this neutron star merger,” says Caltech’s Fred Raab, LIGO associate director for observatory operations. “Today we can say that our gravitational-wave network is working together brilliantly with the light-based observatories to usher in a new era in astronomy, and will improve with the planned addition of observatories in Japan and India.”</p>
<p>LIGO is funded by the<a href="http://www.nsf.gov/">&nbsp;NSF</a>, and operated by&nbsp;<a href="http://www.ligo.caltech.edu/">Caltech</a>&nbsp;and&nbsp;<a href="http://space.mit.edu/LIGO/">MIT</a>, which conceived of LIGO and led the Initial and Advanced LIGO projects.&nbsp;Financial support for the Advanced LIGO project was led by the NSF with Germany (<a href="http://www.mpg.de/en">Max Planck Society</a>), the U.K. (<a href="http://www.stfc.ac.uk/">Science and Technology Facilities Council</a>) and Australia (<a href="http://www.arc.gov.au/">Australian Research Council</a>) making significant commitments and contributions to the project.</p>
<p>More than 1,200 scientists&nbsp;and some 100 <a href="https://my.ligo.org/census.php">institutions</a> from around the world participate in the effort through the <a href="http://ligo.org/">LIGO Scientific Collaboration</a>, which includes the GEO Collaboration and the Australian collaboration OzGrav. Additional partners are listed at&nbsp;<a href="http://ligo.org/partners.php">ligo.org/partners.php</a>.&nbsp;</p>
<p>The Virgo collaboration consists of more than 280 physicists and engineers belonging to 20 different European research groups: six from <a href="http://www.cnrs.fr/">Centre National de la Recherche Scientifique</a> (CNRS) in France; eight from the <a href="http://home.infn.it/it/">Istituto Nazionale di Fisica Nucleare</a> (INFN) in Italy; two in the Netherlands with <a href="https://www.nikhef.nl/en/">Nikhef</a>; the MTA Wigner RCP in Hungary; the POLGRAW group in Poland; the University of Valencia in Spain; and the European Gravitational Observatory,&nbsp;EGO, the laboratory hosting the Virgo detector near Pisa in Italy, funded by CNRS, INFN, and Nikhef.</p>
Artist’s illustration of two merging neutron stars. The rippling space-time grid represents gravitational waves that travel out from the collision, while the narrow beams show the bursts of gamma rays that are shot out just seconds after the gravitational waves. Swirling clouds of material ejected from the merging stars are also depicted. The clouds glow with visible and other wavelengths of light.
Image: National Science Foundation/LIGO/Sonoma State University/A. SimonnetAstronomy, Astrophysics, Physics, Kavli Institute, LIGO, National Science Foundation (NSF), School of Science, Space, astronomy and planetary scienceStanislaw Olbert, professor emeritus of physics and a pioneering theorist of the space age, dies at 94https://news.mit.edu/2017/stanislaw-olbert-physics-professor-emeritus-and-pioneering-theorist-space-age-dies-1003
Olbert researched measurements of solar wind with instruments on several NASA space missions, including the Voyager probes. Tue, 03 Oct 2017 17:10:01 -0400Sandi Miller | Department of Physicshttps://news.mit.edu/2017/stanislaw-olbert-physics-professor-emeritus-and-pioneering-theorist-space-age-dies-1003<p><a href="http://web.mit.edu/physics/people/faculty/olbert_stanislaw.html" target="_blank">Stanislaw “Stan” Olbert</a> PhD ’53, professor emeritus of physics and a distinguished researcher with MIT’s <a href="http://web.mit.edu/space/www/" target="_blank">Space Plasma Group</a>, died from a heart attack on Sept. 23. He was 94.</p>
<p>Olbert fought with the Polish underground during World War II, came to MIT on a scholarship to earn his doctorate, and, as a member of MIT’s Space Plasma Group, was one of the pioneer theorists of the space age. He specialized in the understanding of the solar wind, the streams of atomic particles flowing outward from the sun. He participated in, and brought insight to, the measurements of the solar wind with instruments on several NASA space missions, including the <a href="https://en.wikipedia.org/wiki/Voyager_program" target="_blank">Voyager missions</a> to the outer planets and interstellar space.</p>
<p>Born in 1923, Olbert was raised by his widowed mother in a small village in Eastern Poland. He showed early academic promise, and, during the Russian occupation of 1939 to 1941, he concentrated in math and physics under Russian teachers. Under the subsequent German occupation of 1941, however, his studies were interrupted. He was forced to work as a mason, and later, because he spoke German, as a bookkeeper on a German-run farm. He secretly shared information about German-bound food shipments for later interception by the Polish underground.&nbsp;&nbsp;&nbsp;</p>
<p>In 1944, he fought in the Warsaw uprising and, at the surrender, was taken prisoner by the Germans. At the war’s end, Olbert was declared a "displaced person" and enrolled at the University of Munich to resume his studies in math and physics. He earned a scholarship to the doctoral program of MIT’s Department of Physics in 1949. With the Cosmic Ray Group led by Professor <a href="http://news.mit.edu/1993/rossi-1201" target="_self">Bruno Rossi</a>, he earned his doctorate in 1953, became an assistant professor in 1957, and became full professor in 1967; he retired in 1988.</p>
<p>Following his thesis research, Olbert studied the properties of high-energy nuclear interactions and the extensive air showers — large cascades of atomic particles propagating through the atmosphere — that are produced by those interactions. This provided the first theoretical framework in which the implications of various assumptions about the basic cascade processes could be worked out for comparison with observed shower phenomena.</p>
<p>Olbert’s research in the field of space plasmas began with a study of the origins of cosmic rays in our galaxy. This work, performed in collaboration with Rossi and Professor Philip Morrison, led Olbert into fundamental investigations of individual and collective behavior of charged particles in the interplanetary environment.</p>
<p>The results of these investigations became the basis of two MIT graduate courses. One of these, taught in collaboration with Rossi, led to the publication of a textbook on the subject, "<a href="https://www.amazon.com/Introduction-Physics-Space-Olbert-Rossi/dp/0070538298/ref=sr_1_1?s=books&amp;ie=UTF8&amp;qid=1506612965&amp;sr=1-1&amp;keywords=%22Introduction+to+the+Physics+of+Space%22">Introduction to the Physics of Space</a>" (McGraw-Hill, 1970).</p>
<p>“Professor Olbert was the theoretical backbone of MIT’s Space Plasma Group,” said his colleague <a href="http://web.mit.edu/physics/people/faculty/bradt_hale.html" target="_blank">Hale Bradt</a>, professor emeritus of physic<em>s</em>. The group flew instruments in numerous space missions to study the solar wind, beginning with its first in situ measurement with Explorer 10 in 1961, and including the 1977 launches of <a href="http://web.mit.edu/space/www/voyager_science.html" target="_blank">Voyager I and Voyager II</a>. Even today, the Voyagers continue to send data from in and beyond the heliosphere. Among other contributions, Olbert engaged in theoretical studies of a variety of mechanisms that could be responsible for the generation of stellar winds.</p>
<p>From 1979 to 1986, Olbert undertook two major research projects: the self-consistent solution of the problem of solar wind dynamics, and theoretical studies of radiation generated by solid conductors moving through a magnetized plasma. Olbert maintained contact with many graduate and undergraduate students who have since become well-known in the field of space research.</p>
<p>“He gave me private lessons on the physics of space plasmas, which had not been covered in my coursework,” said Olbert’s last doctoral student, Alan Barnett PhD ’83. “His cheerful and optimistic outlook was infectious.”</p>
<p>In the 1980s, Olbert was a frequent visitor to the University of Rome and the Arcetri Observatory in Florence; and, in 1991, at the Institute for Cosmic Studies in Warsaw, Poland. He collaborated abroad and at home with former students and associates on various projects. One of these papers, in 2003, provides methods for the visualization of the motion of electromagnetic fields that have been used in the teaching of freshman physics both at MIT and around the world. His last first-author paper was published in 2012, at the age of 89. Until late in his life, Olbert kept up with current events with regular reading of newspapers in German, Italian, Polish, and English.</p>
<p>He and his family lived in Melrose, Massachusetts, and later in Cambridge, with summers spent on their New Hampshire farm. Olbert is survived by his wife, Norma (DeVivo), and their two children, Thomas of Cambridge, and Elizabeth of Farmington, Maine, where she is adjunct professor at the University of Maine.</p>
<p>In 1980, Elizabeth created the abstract painting "<a href="http://space.mit.edu/sites/default/files/media/Jupiter_painting_1980_0.pdf" target="_blank">Jupiter</a>," inspired by the Voyager spacecraft images; it hangs in the headquarters of MIT’s Kavli Institute for Astrophysics and Space Research. In 2014, Norma published a biography of Olbert’s early years in Poland and Germany, "<a href="https://www.amazon.com/Boy-Lw%C3%B3w-Norma-Olbert/dp/1500455695">The Boy from Lwów</a>" (CreateSpace, 2014), for which Thomas wrote the foreword and Elizabeth designed the cover.</p>
<p>Olbert’s body was cremated, and there will be no funeral service. A memorial gathering will be announced in the near future.</p>
Stanislaw OlbertPhoto: Department of PhysicsFaculty, Obituaries, Physics, Space, astronomy and planetary science, NASA, School of ScienceMIT physicist Rainer Weiss shares Nobel Prize in physicshttps://news.mit.edu/2017/mit-physicist-rainer-weiss-shares-nobel-prize-physics-1003
LIGO inventor and professor emeritus of physics recognized “for decisive contributions to the LIGO detector and the observation of gravitational waves.”Tue, 03 Oct 2017 06:12:32 -0400Jennifer Chu | MIT News Officehttps://news.mit.edu/2017/mit-physicist-rainer-weiss-shares-nobel-prize-physics-1003<p>Rainer Weiss ’55, PhD ’62, professor emeritus of physics at MIT, has won the Nobel Prize in physics for 2017. Weiss won half of the prize, with the other half of the award shared by Kip S. Thorne, professor emeritus of theoretical physics at Caltech, and Barry C. Barish, professor emeritus of physics at Caltech.</p>
<p>The Nobel Foundation, in its announcement this morning, cited the physicists <em>"</em>for decisive contributions to the LIGO detector and the observation of gravitational waves.”</p>
<p>“We are immensely proud of Rai Weiss, and we also offer admiring best wishes to his chief collaborators and the entire LIGO team,” says MIT President L. Rafael Reif. “The creativity and rigor of the LIGO experiment constitute a scientific triumph; we are profoundly inspired by the decades of ingenuity, optimism, and perseverance that made it possible. It is especially sweet that Rai Weiss not only served on the MIT faculty for 37 years, but is also an MIT graduate. Today’s announcement reminds us, on a grand scale, of the value and power of fundamental scientific research and why it deserves society’s collective support.”</p>
<p>At a press conference held today at MIT, Weiss credited his hundreds of colleagues who have helped to push forward the search for gravitational waves.</p>
<p>“The discovery has been the work of a large number of people, many of whom played crucial roles,” Weiss said. “I view receiving this [award] as sort of a symbol of the various other people who have worked on this.”</p>
<p>In describing what the award means to him in a larger context, Weiss said: “This prize and others that are given to scientists is an affirmation by our society of [the importance of] gaining information about the world around us from reasoned understanding of evidence."</p>
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<p><strong>Listening for a wobble</strong></p>
<p>On Sept. 14, 2015, at approximately 5:51 a.m. EDT, a gravitational wave — a ripple from a distant part of the universe — passed through the Earth, generating an almost imperceptible, fleeting wobble in the world that would have gone completely unnoticed save for two massive, identical instruments, designed to listen for such cosmic distortions.</p>
<p>The Laser Interferometer Gravitational-wave Observatory, or LIGO, consists of two L-shaped interferometers, each 4 kilometers in length, separated by 1,865 miles. On Sept. 14, 2015, scientists picked up a very faint wobble in the instruments and soon confirmed that the interferometers had been infinitesimally stretched — by just one-ten-thousandth the diameter of a proton — and that this minuscule distortion arose from a passing gravitational wave.</p>
<p>The LIGO Scientific Collaboration, with the Caltech-MIT LIGO Laboratory and more than 1,000 scientists at universities and observatories around the world, confirmed the signal as the first direct detection of a gravitational wave by an instrument on Earth. The scientists further decoded the signal to determine that the gravitational wave was the product of a violent collision between two massive black holes 1.3 billion years ago.</p>
<p>The momentous result confirmed the theory of general relativity proposed by Albert Einstein, who almost exactly 100 years earlier had predicted the existence of gravitational waves but assumed that they would be virtually impossible to detect from Earth. Since this first discovery, LIGO has detected three other gravitational wave signals, also generated by pairs of spiraling, colliding black holes; the most announced of a detection came <a href="http://news.mit.edu/2017/gravitational-waves-binary-black-hole-merger-observed-ligo-and-virgo-0927">just last week</a>.</p>
<p>“We are incredibly proud of Rai and his colleagues for their vision and courage that led to this great achievement,” says Michael Sipser, the Donner Professor of Mathematics and dean of the School of Science at MIT.&nbsp;“It is a wonderful day for them, for MIT, for risk-taking and boldness, and for all of science.”</p>
<p><strong>A gravitational blueprint</strong></p>
<p>The detection was an especially long-awaited payoff for Weiss, who came up with the initial design for LIGO some 50 years ago. He has since been instrumental in shaping and championing the idea as it developed from a desktop prototype to LIGO’s final, observatory-scale form.</p>
<p>In 1967, Weiss, then an assistant professor of physics at MIT, was asked by his department to teach an introductory course in general relativity — a subject he knew little about. A few years earlier, the American physicist Joseph Weber had claimed to have made the first detection of gravitational waves, using resonant bars — long, aluminum cylinders that should ring at a certain frequency in response to a gravitational wave. When his students asked him to explain how these Weber bars worked, Weiss found that he couldn’t.</p>
<p>No one in the scientific community had been able to replicate Weber’s results. Weiss had a very different idea for how to do it, and assigned the problem to his students, instructing them to design the simplest experiment they could to detect a gravitational wave. Weiss himself came up with a design: Build an L-shaped interferometer and shine a light down the length of each arm, at the end of which hangs a free-floating mirror. The lasers should bounce off the mirrors and head back along each arm, arriving where they started at the exact same time. If a gravitational wave passes through, it should “stretch” or displace the mirrors ever so slightly, and thus change the lasers’ arrival times.</p>
<p>Weiss refined the idea over a summer in MIT’s historic Building 20, a wooden structure built during World War II to develop radar technology. The building, meant to be temporary and known to many as the “Plywood Palace,” lived on to germinate and support innovative, high-risk projects. During that time, Weiss came to the conclusion that his design could indeed detect gravitational waves, if built to large enough dimensions. His design would serve as the essential blueprint for LIGO.</p>
<p><strong>An observatory takes shape</strong></p>
<p>To test his idea, Weiss initially built a 1.5-meter prototype. But to truly detect a gravitational wave, the instrument would have to be several thousand times longer: The longer the interferometer’s arms, the more sensitive its optics are to minute displacements.</p>
<p>To realize this audacious design, Weiss teamed up in 1976 with noted physicist Kip Thorne, who, based in part on conversations with Weiss, soon started a gravitational wave experiment group at Caltech. The two formed a collaboration between MIT and Caltech, and in 1979, the late Scottish physicist Ronald Drever, then of Glasgow University, joined the effort at Caltech. The three scientists — who became the co-founders of LIGO — worked to refine the dimensions and scientific requirements for an instrument sensitive enough to detect a gravitational wave.</p>
<p>Barry Barish soon joined the team as first a principal investigator, then director of the project, and was instrumental in securing funding for the audacious project, and bringing the detectors to completion.</p>
<p>After years of fits and starts in research and funding, the project finally received significant and enthusiastic backing from the National Science Foundation, and in the mid-1990s, LIGO broke ground, erecting its first interferometer in Hanford, Washington, and its second in Livingston, Louisiana.</p>
<p>Prior to making their seminal detection two years ago, LIGO’s detectors required years of fine-tuning to improve their sensitivity. During this time, Weiss not only advised on scientific quandaries but also stepped in to root out problems in the detectors themselves. Weiss is among the few to have walked the length of the interferometers’ tunnels in the space between LIGO’s laser beam tube and its encasement. Inspecting the detectors in this way, Weiss would often discover minute cracks, tiny shards of glass, and even infestations of wasps, mice, and black widow spiders, which he would promptly deal with.</p>
<p><strong>A cosmic path</strong></p>
<p>Weiss was born in 1932 in tumultuous Berlin. When his mother, Gertrude Loesner, was pregnant with Weiss, his father, neurologist Frederick Weiss, was abducted by the Nazis for testifying against a Nazi doctor. He was eventually released with the help of Loesner’s family. The young family fled to Prague and then emigrated to New York City, where Weiss grew up on Manhattan’s Upper West Side, cultivating a love for classical music and electronics, and making a hobby of repairing radios.</p>
<p>After graduating high school, he went to MIT to study electrical engineering, in hopes of finding a way to quiet the hiss heard in shellac records. He later switched to physics, but then dropped out of school in his junior year, only to return shortly after, taking a job as a technician in Building 20. There, Weiss met physicist Jerrold Zacharias, who is credited with developing the first atomic clock. Zacharias encouraged and supported Weiss in finishing his undergraduate degree in 1955 and his PhD in 1962.</p>
<p>Weiss spent some time at Princeton University as a postdoc, where he developed experiments to test gravity, before returning to MIT as an assistant professor in 1964. In the midst of his work in gravitational wave detection, Weiss also investigated and became a leading researcher in cosmic microwave background radiation — thermal radiation, found in the microwave band of the radio spectrum, that is thought to be a diffuse afterglow from the Big Bang.</p>
<p>In 1976, Weiss was appointed to oversee a scientific working group for NASA’s Cosmic Background Explorer (COBE) satellite, which launched in 1989 and went on to precisely measure microwave radiation and its tiny, quantum fluctuations. Weiss was co-founder and chair of the science working group for the mission, whose measurements helped support the Big Bang theory of the universe. COBE’s findings earned two of its principal investigators the Nobel Prize in physics in 2006.</p>
<p>Weiss has received numerous awards and honors, including the Medaille de l’ADION, the 2006 Gruber Prize in Cosmology, and the 2007 Einstein Prize of the American Physical Society. He is a fellow of the American Association for the Advancement of Science, the American Academy of Arts and Sciences, and the American Physical Society, as well as a member of the National Academy of Sciences. In 2016, Weiss received a Special Breakthrough Prize in Fundamental Physics, the Gruber Prize in Cosmology, the Shaw Prize in Astronomy, and the Kavli Prize in Astrophysics, all shared with Drever and Thorne. Most recently, Weiss shared the Princess of Asturias Award for Technical and Scientific Research with Thorne, Barry Barish of Caltech, and the LIGO Scientific Collaboration.</p>
Rainer Weiss at home early this morning, after learning that he has won the 2017 Nobel Prize in physics.Photo: M. Scott BrauerAstrophysics, awards, Awards, honors and fellowships, LIGO, Black holes, Faculty, History, History of science, History of MIT, Kavli Institute, National Science Foundation (NSF), Nobel Prizes, Physics, Research, School of Science, Space, astronomy and planetary scienceGravitational waves from a binary black hole merger observed by LIGO and Virgohttps://news.mit.edu/2017/gravitational-waves-binary-black-hole-merger-observed-ligo-and-virgo-0927
Finding represents first joint detection of gravitational waves with both detectors.Wed, 27 Sep 2017 14:00:00 -0400MIT News Officehttps://news.mit.edu/2017/gravitational-waves-binary-black-hole-merger-observed-ligo-and-virgo-0927<p><em>The following news article is adapted from a press release issued by the Laser Interferometer Gravitational-wave Observatory (LIGO) Laboratory, in partnership with the </em><a href="http://www.ligo.org/"><em>LIGO Scientific Collaboration</em></a><em> and </em><a href="http://www.virgo-gw.eu/"><em>Virgo Collaboration</em></a><em>. LIGO is funded by the National Science Foundation (NSF) and operated by Caltech and MIT, which conceived and built the project.</em></p>
<p>The LIGO Scientific Collaboration and the Virgo collaboration report the first joint detection of gravitational waves with both the LIGO and Virgo detectors. This is the fourth announced detection of a binary black hole system and the first significant gravitational-wave signal recorded by the Virgo detector, and highlights the scientific potential of a three-detector network of gravitational-wave detectors.</p>
<p>The three-detector observation was made on Aug. 14 at 10:30:43 UTC. The two Laser Interferometer Gravitational-wave Observatory (LIGO) detectors, located in Livingston, Louisiana, and Hanford, Washington, and funded by the National Science Foundation (NSF), and the Virgo detector, located near Pisa, Italy, detected a transient gravitational-wave signal produced by the coalescence of two stellar mass black holes.</p>
<p>A paper about the event, known as GW170814, has been accepted for publication in the journal <em>Physical Review Letters</em>.</p>
<p>The detected gravitational waves — ripples in space and time — were emitted during the final moments of the merger of two black holes with masses about 31 and 25 times the mass of the sun and located about 1.8 billion light years away. The newly produced spinning black hole has about 53 times the mass of our sun, which means that about three solar masses were converted into gravitational-wave energy during the coalescence.</p>
<p>“This is just the beginning of observations with the network enabled by Virgo and LIGO working together,” says David Shoemaker of MIT, who is the spokesperson for the LIGO Scientific Collaboration. “With the next observing run planned for fall 2018 we can expect such detections weekly or even more often.”</p>
<p>“It is wonderful to see a first gravitational-wave signal in our brand new Advanced Virgo detector only two weeks after it officially started taking data,” says Jo van den Brand of Nikhef and VU University Amsterdam, who is spokesperson for the Virgo collaboration. “That’s a great reward after all the work done in the Advanced Virgo project to upgrade the instrument over the past six years.”</p>
<p>“Little more than a year and a half ago, NSF announced that its Laser Gravitational-wave Observatory had made the first-ever detection of gravitational waves resulting from the collision of two black holes in a galaxy a billion light-years away," says France Córdova, NSF director. "Today, we are delighted to announce the first discovery made in partnership between the Virgo Gravitational-Wave Observatory and the LIGO Scientific Collaboration, the first time a gravitational-wave detection was observed by these observatories, located thousands of miles apart. This is an exciting milestone in the growing international scientific effort to unlock the extraordinary mysteries of our universe.” &nbsp;</p>
<p>Advanced LIGO is a second-generation gravitational-wave detector consisting of the two identical interferometers in Hanford and Livingston, and uses precision laser interferometry to detect gravitational waves. Beginning operation in September 2015, Advanced LIGO has conducted two observing runs. The second “O2” observing run began on Nov. 30, 2016 and ended on Aug. 25, 2017.&nbsp;</p>
<p>Advanced Virgo is a second-generation instrument built and operated by the Virgo collaboration to search for gravitational waves. With the end of observations with the initial Virgo detector in October 2011, the integration of the Advanced Virgo detector began. The new facility was dedicated this past February, while its commissioning was ongoing. In April, the control of the detector at its nominal working point was achieved for the first time.</p>
<p>The Virgo detector joined the O2 run on Aug. 1, at 10:00 UTC. The real-time detection on Aug. 14 was triggered with data from all three LIGO and Virgo instruments. Virgo is, at present, less sensitive than LIGO, but two independent search algorithms based on all the information available from the three detectors demonstrated the evidence of a signal in the Virgo data as well.</p>
<p>Overall, the volume of universe that is likely to contain the source shrinks by more than a factor of 20 when moving from a two-detector network to a three-detector network. The sky region for GW170814 has a size of only 60 square degrees, less than one-tenth the region size with data from the two LIGO interferometers alone; in addition, the accuracy with which the source distance is measured benefits from the addition of Virgo.</p>
<p>“This increased precision will allow the entire astrophysical community to eventually make even more exciting discoveries, including multimessenger observations,” says Georgia Tech Professor Laura Cadonati, the deputy spokesperson for the LSC.&nbsp;“A smaller search area enables follow-up observations with telescopes and satellites for cosmic events that produce gravitational waves and emissions of light, such as the collision of neutron stars.”</p>
<p>“As we increase the number of observatories in the international gravitational wave network, we not only improve the source location, but we also recover improved polarization information that provides better information on the orientation of the orbiting objects as well as enabling new tests of Einstein’s theory,” says Fred Raab, LIGO associate director for observatory operations.</p>
<p><br />
LIGO and Virgo’s partner electromagnetic facilities around the world didn’t identify a counterpart for GW170814, which was similar to the three prior LIGO observations of black hole mergers. Black holes produce gravitational waves but not light.&nbsp;&nbsp;</p>
<p>“With this first joint detection by the Advanced LIGO and Virgo detectors, we have taken one step further into the gravitational-wave cosmos,” says Caltech’s David H. Reitze, the executive director of the LIGO Laboratory. “Virgo brings a powerful new capability to detect and better locate gravitational-wave sources, one that will undoubtedly lead to exciting and unanticipated results in the future.”&nbsp;&nbsp;</p>
<p>LIGO is funded by NSF and operated by&nbsp;Caltech&nbsp;and&nbsp;MIT,&nbsp;which conceived and built the project. Financial support for the Advanced LIGO project was led by NSF with Germany (Max Planck Society), the U.K. (Science and Technology Facilities Council) and Australia (Australian Research Council) making significant commitments and contributions to the project. More than 1,200 scientists from around the world participate in the effort through the LIGO Scientific Collaboration, which includes the GEO Collaboration.&nbsp;Additional partners are listed at&nbsp;<a href="http://mit.pr-optout.com/Tracking.aspx?Data=HHL%3d8158%3d4-%3eLCE9%3b4%3b8%3f%26SDG%3c90%3a.&amp;RE=MC&amp;RI=5328430&amp;Preview=False&amp;DistributionActionID=37231&amp;Action=Follow+Link">ligo.org/partners.php</a>.</p>
<p>The Virgo collaboration consists of more than 280 physicists and engineers belonging to 20 different European research groups: six from Centre National de la Recherche Scientifique (CNRS) in France; eight from the Istituto Nazionale di Fisica Nucleare (INFN) in Italy; two in The Netherlands with Nikhef; the MTA Wigner RCP in Hungary; the POLGRAW group in Poland; Spain with the University of Valencia; and EGO, the laboratory hosting the Virgo detector near Pisa in Italy.</p>
An aerial view of the Virgo site shows the Mode-Cleaner building, the Central building, the 3km-long west arm and the beginning of the north arm. The other buildings include offices, workshops, computer rooms and the control room of the interferometer.
Image: The Virgo collaboration/CCO 1.0Astronomy, Astrophysics, Black holes, Kavli Institute, LIGO, Research, School of Science, Space, astronomy and planetary science, National Science Foundation (NSF), PhysicsAstronaut Kate Rubins returns to the Whitehead Institute to describe her experiences in low-Earth orbithttps://news.mit.edu/2017/astronaut-kate-rubins-returns-to-whitehead-institute-to-describe-space-experiences-0920
Former Whitehead Fellow and recent International Space Station resident gives public talk and engages with the next generation of scientists and engineers.Wed, 20 Sep 2017 15:35:04 -0400Nicole Giese | Whitehead Institutehttps://news.mit.edu/2017/astronaut-kate-rubins-returns-to-whitehead-institute-to-describe-space-experiences-0920<p>The Whitehead Institute at MIT welcomed NASA astronaut and former Whitehead Fellow Kathleen “Kate” Rubins on Sept. 12.</p>
<p>Rubins' visit began in the afternoon, when Whitehead Institute Director David Page interviewed her for Whitehead’s podcast, "Audiohelicase." After the interview, Rubins spoke with a select group of Whitehead postdocs and graduate students.</p>
<p>Later, she enthralled local students as she recounted her four-month 2016 trip to the International Space Station (ISS), her biomedical research in space, and her journey from scientist to astronaut. The audience of students, teachers, and parents from Cambridge and surrounding communities watched with rapt attention as Rubins narrated a video showing her preparations for and launch into space, her experiments — including the first DNA sequencing in space — her fiery return to Earth in a plasma-surrounded capsule, and her jarring landing on the Kazakh Steppe, in Kazakhstan.</p>
<p>Following the video, Rubins answered many probing questions from the attendees, including whether she hopes to go back into space. With a laugh, she answered that she would love to visit the space station again, but as she had just returned, she was most likely at the bottom of NASA’s list right now.</p>
<p>That evening, Rubins headlined Whitehead Connects, an initiative of the Whitehead Institute at MIT that brings notable biology and biotech leaders to campus for engaging public presentations. The event began in a packed Whitehead Auditorium with remarks and an introduction by Maria Zuber, MIT vice president for research, the E. A. Griswold Professor of Geophysics in the Department of Earth, Atmospheric and Planetary Sciences. In her role as vice president for research, Zuber oversees more than a dozen of MIT’s research institutes and laboratories, as well as MIT’s Lincoln Laboratory, and is also responsible for research compliance, intellectual property, and projects with the federal government. In addition, Zuber has been chair of the National Science Board since 2016.</p>
<p>Zuber spoke about the current landscape of federal funding for science and the criticality of federal funds for keeping scientific discovery moving forward. She described how her own experiences with over half a dozen NASA planetary missions underscored for her how much there is yet to be discovered, and how work like Rubins’ — at the intersection of space exploration and the life sciences — is an endeavor of utmost importance. Zuber then welcomed Rubins back to the Institute.</p>
<p>Before a capacity crowd, Rubins&nbsp;detailed her experience as a NASA astronaut and her path from Whitehead to NASA. As a&nbsp;Whitehead Fellow&nbsp;from 2007 to 2009,&nbsp;Rubins and her&nbsp;lab were focused on understanding the viruses causing Ebola and Marburg virus diseases, as well as Lassa fever. Her work also included special projects with the U.S. Army that aimed to develop therapies for Ebola and Lassa fever.</p>
<p>Rubins was selected as one of 14 NASA astronaut candidates in 2009, and after extensive training was assigned to Expeditions 48 and 49 onboard the International Space Station. Last year, Rubins spent nearly four months aboard the ISS, from July to October. Among her many accomplishments, she logged over 12 hours of spacewalk time and became the first person to sequence DNA in space.</p>
<p>Rubins shared with the Whitehead Connects audience a video detailing her mission, including the trials of living and working in microgravity, some of the more than 275 scientific experiments done by the crew, as well as her work growing heart cells in a dish, doing quantitative, real-time PCR, and microbiome experiments.</p>
<p>The video was followed by an interactive question-and-answer period moderated by Richard Young, Whitehead member and professor of biology at MIT. The evening concluded with a reception welcoming Rubins back to Whitehead and honoring her extraordinary accomplishments.</p>
<p>For more information about Whitehead Connects and other upcoming events at the Whitehead Institute, please visit <a href="http://wi.mit.edu" target="_blank">wi.mit.edu</a>.</p>
NASA astronaut and former Whitehead Fellow Kathleen "Kate" Rubins returned to MIT for a public talk and engagement with local students. Photo: Allegra BovermanSpace, astronomy and planetary science, NASA, Special events and guest speakers, Whitehead Institute, Biology, School of ScienceMathematics predicts a sixth mass extinctionhttps://news.mit.edu/2017/mathematics-predicts-sixth-mass-extinction-0920
By 2100, oceans may hold enough carbon to launch mass extermination of species in future millennia.Wed, 20 Sep 2017 14:00:00 -0400Jennifer Chu | MIT News Officehttps://news.mit.edu/2017/mathematics-predicts-sixth-mass-extinction-0920<p>In the past 540 million years, the Earth has endured five mass extinction events, each involving processes that upended the normal cycling of carbon through the atmosphere and oceans. These globally fatal perturbations in carbon each unfolded over thousands to millions of years, and are coincident with the widespread extermination of marine species around the world.&nbsp;</p>
<p>The question for many scientists is whether the carbon cycle is now experiencing a significant jolt that could tip the planet toward a sixth mass extinction. In the modern era, carbon dioxide emissions have risen steadily since the 19th century, but deciphering whether this recent spike in carbon could lead to mass extinction has been challenging. That’s mainly because it’s difficult to relate ancient carbon anomalies, occurring over thousands to millions of years, to today’s disruptions, which have taken place over just a little more than a century.</p>
<p>Now Daniel Rothman, professor of geophysics in the MIT Department of Earth, Atmospheric and Planetary Sciences and co-director of MIT’s Lorenz Center, has analyzed significant changes in the carbon cycle over the last 540 million years, including the five mass extinction events. He has identified “thresholds of catastrophe” in the carbon cycle that, if exceeded, would lead to an unstable environment, and ultimately, mass extinction.</p>
<p>In a paper published today in <em>Science Advances</em>, he proposes that mass extinction occurs if one of two thresholds are crossed: For changes in the carbon cycle that occur over long timescales, extinctions will follow if those changes occur at rates faster than global ecosystems can adapt. For carbon perturbations that take place over shorter timescales, the pace of carbon-cycle changes will not matter; instead, the size or magnitude of the change will determine the likelihood of an extinction event.&nbsp;</p>
<p>Taking this reasoning forward in time, Rothman predicts that, given the recent rise in carbon dioxide emissions over a relatively short timescale, a sixth extinction will depend on whether a critical amount of carbon is added to the oceans. That amount, he calculates, is about 310 gigatons, which he estimates to be roughly equivalent to the amount of carbon that human activities will have added to the world’s oceans by the year 2100.</p>
<p>Does this mean that mass extinction will soon follow at the turn of the century? Rothman says it would take some time — about 10,000 years — for such ecological disasters to play out. However, he says that by 2100 the world may have tipped into “unknown territory.”</p>
<p>“This is not saying that disaster occurs the next day,” Rothman says. “It’s saying that, if left unchecked, the carbon cycle would move into a realm which would be no longer stable, and would behave in a way that would be difficult to predict. In the geologic past, this type of behavior is associated with mass extinction.”</p>
<p><strong>History follows theory</strong></p>
<p>Rothman had previously done work on the end-Permian extinction, the most severe extinction in Earth’s history, in which a massive pulse of carbon through the Earth’s system was involved in wiping out more than 95 percent of marine species worldwide. Since then, conversations with colleagues spurred him to consider the likelihood of a sixth extinction, raising an essential question:</p>
<p>“How can you really compare these great events in the geologic past, which occur over such vast timescales, to what’s going on today, which is centuries at the longest?” Rothman says. “So I sat down one summer day and tried to think about how one might go about this systematically.”</p>
<p>He eventually derived a simple mathematical formula based on basic physical principles that relates the critical rate and magnitude of change in the carbon cycle to the timescale that separates fast from slow change. He hypothesized that this formula should predict whether mass extinction, or some other sort of global catastrophe, should occur.</p>
<p>Rothman then asked whether history followed his hypothesis. By searching through hundreds of published geochemistry papers, he identified 31 events in the last 542 million years in which a significant change occurred in Earth’s carbon cycle. For each event, including the five mass extinctions, Rothman noted the change in carbon, expressed in the geochemical record as a change in the relative abundance of two isotopes, carbon-12 and carbon-13. He also noted the duration of time over which the changes occurred.</p>
<p>He then devised a mathematical transformation to convert these quantities into the total mass of carbon that was added to the oceans during each event. Finally, he plotted both the mass and timescale of each event.</p>
<p>“It became evident that there was a characteristic rate of change that the system basically didn’t like to go past,” Rothman says.</p>
<p>In other words, he observed a common threshold that most of the 31 events appeared to stay under. While these events involved significant changes in carbon, they were relatively benign — not enough to destabilize the system toward catastrophe. In contrast, four of the five mass extinction events lay over the threshold, with the most severe end-Permian extinction being the farthest over the line.&nbsp;</p>
<p>“Then it became a question of figuring out what it meant,” Rothman says.</p>
<p><strong>A hidden leak</strong></p>
<p>Upon further analysis, Rothman found that the critical rate for catastrophe is related to a hidden process within the Earth’s natural carbon cycle. The cycle is essentially a loop between photosynthesis and respiration. Normally, there is a “leak” in the cycle, in which a small amount of organic carbon sinks to the ocean bottom and, over time, is buried as sediment and sequestered from the rest of the carbon cycle.</p>
<p>Rothman found that the critical rate was equivalent to the rate of excess production of carbon dioxide that would result from plugging the leak. Any additional carbon dioxide injected into the cycle could not be described by the loop itself. One or more other processes would instead have taken the carbon cycle into unstable territory.</p>
<p>He then determined that the critical rate applies only beyond the timescale at which the marine carbon cycle can re-establish its equilibrium after it is disturbed. Today, this timescale is about 10,000 years. For much shorter events, the critical threshold is no longer tied to the rate at which carbon is added to the oceans but instead to the carbon’s total mass. Both scenarios would leave an excess of carbon circulating through the oceans and atmosphere, likely resulting in global warming and ocean acidification.</p>
<p><strong>The century</strong><strong>’</strong><strong>s the limit</strong></p>
<p>From the critical rate and the equilibrium timescale, Rothman calculated the critical mass of carbon for the modern day to be about 310 gigatons.</p>
<p>He then compared his prediction to the total amount of carbon added to the Earth’s oceans by the year 2100, as projected in the most recent report of the Intergovernmental Panel on Climate Change. The IPCC projections consider four possible pathways for carbon dioxide emissions, ranging from one associated with stringent policies to limit carbon dioxide emissions, to another related to the high range of scenarios with no limitations.</p>
<p>The best-case scenario projects that humans will add 300 gigatons of carbon to the oceans by 2100, while more than 500 gigatons will be added under the worst-case scenario, far exceeding the critical threshold. In all scenarios, Rothman shows that by 2100, the carbon cycle will either be close to or well beyond the threshold for catastrophe.</p>
<p>“There should be ways of pulling back [emissions of carbon dioxide],” Rothman says. “But this work points out reasons why we need to be careful, and it gives more reasons for studying the past to inform the present.”</p>
<p>This research was supported, in part, by NASA and the National Science Foundation.</p>
“This is not saying that disaster occurs the next day,” says Professor Daniel Rothman about his new study. “It’s saying that, if left unchecked, the carbon cycle would move into a realm which would be no longer stable, and would behave in a way that would be difficult to predict. In the geologic past, this type of behavior is associated with mass extinction.”
Climate change, Lorenz Center, EAPS, Earth and atmospheric sciences, Emissions, Environment, Geology, Global Warming, Greenhouse gases, Research, School of Science, NASA, National Science Foundation (NSF)Neighboring exoplanets may hold water, study findshttps://news.mit.edu/2017/neighboring-exoplanets-may-hold-water-0831
Observations and modeling suggest TRAPPIST-1 exoplanets may have held onto water, billions of years after their formation.Thu, 31 Aug 2017 09:59:59 -0400Jennifer Chu | MIT News Officehttps://news.mit.edu/2017/neighboring-exoplanets-may-hold-water-0831<p>Seven Earth-sized exoplanets circle the ultracool dwarf star TRAPPIST-1, just 40 light-years from our own blue planet. Now an international team of scientists at the Geneva Observatory in Switzerland, MIT, and elsewhere, report that the outer planets in this system may still hold significant stores of water. Three of these potential water worlds are also considered within the habitable zone of the star, giving further support to the possibility that these neighboring planets may, in fact, be hospitable to life.</p>
<p>The team’s results, published today in <em>The Astronomical Journal</em>, are based on observations of the TRAPPIST-1 star made by the NASA/ESA Hubble Space Telescope. The researchers trained the telescope on the star to measure its current ultraviolet radiation, and used these measurements to estimate how the star’s energy changed over the course of billions of years. They then modeled how the star’s energy may have affected the water resources on each of the TRAPPIST-1 exoplanets over the last 8 billion years. &nbsp;&nbsp;</p>
<p>Scientists’ current knowledge of the system suggests that these planets originally formed much farther out from their star, in a cold zone populated with crystals of water ice, which the planets likely captured as they came together, potentially creating tremendous stores of water, both in the planets’ interiors and on their surfaces.</p>
<p>From their observations and modeling, the researchers conclude that, over the past 8 billion years, heat and radiation from the star may have caused the innermost planets to lose more than 20 times the amount of water in all of Earth’s oceans. Meanwhile, they say, the outer planets would have lost much less, suggesting they could still retain some water on their surfaces and in their interiors.</p>
<p>“In terms of habitability, this is a positive step forward to say that hopes are still high,” says study co-author Julien de Wit, a postdoc in MIT’s Department of Earth, Atmospheric and Planetary Sciences. “This concludes that a few of these outer planets could have been able to hold onto some water, if they accumulated enough during their formation. But we need to gather more information and actually see a hint of water, which we haven’t found yet.”</p>
<p><strong>A water vapor break-up</strong></p>
<p>In February of 2016, de Wit and others from the University of Liege in Belgium <a href="http://news.mit.edu/2016/scientists-discover-potentially-habitable-planets-0502">announced the discovery</a> of the seven Earth-sized planets around TRAPPIST-1. The discovery marked the largest number of Earth-sized planets discovered in a single system.</p>
<p>Since then, de Wit, lead author Vincent Bourrier of the Geneva Observatory,</p>
<p>and an international team of researchers used the Hubble Space Telescope Imaging Spectrograph (STIS) to measure the amount of ultraviolet radiation given off by the TRAPPIST-1 star then received by its planets. If a planet’s atmosphere harbors water vapor, the presence of ultraviolet radiation can act to break up that water vapor, into oxygen and hydrogen — a process that occurs today on Earth. As oxygen is heavier than hydrogen, it sinks towards the surface, while hydrogen rises through the upper atmosphere.</p>
<p>The researchers hoped that by using Hubble’s imaging spectrograph, they might look for signs of hydrogen, particularly around two of the middle planets. The researchers were focused on a very narrow region of the ultraviolet spectrum, called the Lyman-alpha band, which is sensitive to hydrogen. They reasoned that if they picked up traces of hydrogen around either planet, that would suggest the presence of water vapor.</p>
<p>In 2016, the team trained the telescope on the TRAPPIST-1 system over one observing run of five orbits for each planet, totaling eight hours, in which they gathered 4.5 hours of data. Unfortunately, the observations of whether each planet contained hydrogen, and therefore water vapor, were inconclusive.</p>
<p>However, the researchers also obtained measurements of the star’s ultraviolet flux, or the strength of its radiation. They compared these measurements to similar ones made the previous year.</p>
<p>“We see this flux is actually changing, and we can use this change to backtrack and have an understanding of how much energy the star is putting on each planet over the course of the planets’ lives,” de Wit explains.</p>
<p><strong>Oceans lost</strong></p>
<p>Based on previous estimates of the planets’ densities, the scientists assume that the planets likely formed much farther out from their current positions, beyond what is considered the “ice line” — the distance from the star, beyond which space is cold enough for ice crystals to spontaneously form. It’s likely that all seven TRAPPIST-1 planets took shape within this zone, taking up significant volumes of water ice as they formed.</p>
<p>Researchers have also previously observed that the planets’ orbital configurations are such that they likely migrated together, “moving as a pack,” as de Wit describes, eventually taking up their current positions, closer into their star. As they migrated into the star’s warmer zone, the star’s ultraviolet radiation likely started to strip away and evaporate the planets’ water resources.</p>
<p>In their current paper, the scientists used their estimates of the star’s ultraviolet flux over the last 8 billion years to estimate the amount of water the the planets likely lost as they migrated over this period of time, closer in to their star.</p>
<p>The team plugged the estimates of ultraviolet flux into two separate models: an atmospheric model that calculates the amount of water vapor that might be lost given a certain ultraviolet concentration, and a geophysical model that estimates how much water ice and other volatiles, buried deep in a planet’s interior, can be brought back up into the atmosphere via outgassing.</p>
<p>From their modeling, the scientists estimate that the innermost planets lost more than 20 times Earth’s current oceanic water stores over their 8-billion-year journey toward their star, while the outermost planets lost much less, equivalent to around three times the ocean stores on Earth.</p>
<p>“Earth-sized planets can capture hundreds of Earth-oceans’ worth of water when they form, but it’s highly dependent on so many factors, and difficult to say,” de Wit says. “We can say the inner ones probably lost a huge amount of water, and the outer ones way less, allowing them to actually still have some water, if they captured it when they first formed.”</p>
<p>“It depends a lot on their initial water content,” Bourrier adds. “If they formed as ocean planets, even the inner ones would likely still harbor a lot of water. We are still a long way to determining the habitability of these planets, but our results suggest that the outer ones might be the best targets to focus our future observations.”</p>
<p>De Wit and his colleagues are planning another observing run, and will use Hubble to monitor the system more closely, spending more time observing, and trying to look for clouds of hydrogen around each planet as they transit, or cross in front of their star.</p>
<p>“If the planet’s atmosphere holds water vapor, and it is losing hydrogen as it reacts with ultraviolet radiation, it will look a bit like a gigantic comet with a tail, or a sphere that’s 10 times bigger than the planet, filled with atomic hydrogen, that is slowly flowing out of the planet, forming a tail from the stellar wind,” de Wit says. “It’s amazing how quickly our perspective on this [system] has changed. It’s really a steep learning curve that is really exciting.”</p>
<p>This research was supported, in part, by NASA, the Space Science Telescope Institute, the Swiss National Science Foundation, the Simons Foundation, the Belgian National Fund for Scientific Research, and the Gruber Foundation.</p>
This artist’s impression shows the view from the surface of one of the planets in the TRAPPIST-1 system. At least seven planets orbit this ultracool dwarf star 40 light-years from Earth and they are all roughly the same size as the Earth. Several of the planets are at the right distances from their star for liquid water to exist on the surfaces.
Image: ESO/N. Bartmann/spaceengine.orgAstronomy, Astrophysics, EAPS, NASA, Planetary science, Research, School of Science, space, Space, astronomy and planetary scienceExperiencing the Great American Solar Eclipsehttps://news.mit.edu/2017/experiencing-great-american-solar-eclipse-mit-0829
Thousands attend MIT solar eclipse-watching parties on campus, at the MIT Wallace Observatory, and in Rexburg, Idaho. Tue, 29 Aug 2017 14:45:01 -0400Nancy Kotary | Haystack Observatoryhttps://news.mit.edu/2017/experiencing-great-american-solar-eclipse-mit-0829<p>They came in droves to witness the moon blocking the sun.</p>
<p>On Aug. 21 at MIT's campus in Cambridge, Massachusetts; at the MIT Wallace Observatory; and in eastern Idaho, members of the MIT community, and the public at large, gathered to watch what was hailed by many as the Great American Solar Eclipse — a solar eclipse that could be seeen across North America.</p>
<p>The MIT Department of Earth, Atmospheric and Planetary Sciences (EAPS) hosted the main event on campus, at the Kresge Oval. Armed with solar glasses and viewing devices ranging from a pair of specially filtered telescopes to paper plates, colanders, and pinhole cameras, organizers enthusiastically greeted several thousand attendees who showed up to view the partial eclipse. Megan Jordan, EAPS academic administrator, said that the 300 pairs of solar glasses on hand were shared by attendees, whose presence far exceeded the expected turnout. The event, organized by senior lecturer Amanda Bosh and others in EAPS, was well staffed with volunteers, postdocs, and students, as well as individuals in the <a href="http://mailman.mit.edu/mailman/listinfo/observe" target="_blank">observe@MIT</a> stargazing group.</p>
<div class="cms-placeholder-content-video"></div>
<p>In Westford, Massachusetts, the MIT Wallace Astrophysical Observatory and MIT Haystack Observatory co-hosted another lively eclipse party for nearly 200 people on the Wallace grounds — the largest public event ever at the observatory. Despite months of hype and excitement, the partial eclipse did not disappoint here, either. Families gathered on the lawn from as far away as Virgina to see what looked like a bite taken out of the sun. Cool temperatures and a dimmed sky during the height of the obscurement were clearly noticable, even though the moon covered just over 60 percent of the sun's surface.&nbsp;</p>
<p>Several families built and transported carboard viewers larger than the children using them to safely watch the sun. MIT Wallace site manager Tim Brothers set up a telescope filtered for safe viewing, and the line of people waiting to look through it at the eclipse stretched through the grounds during the entire eclipse party. Brothers also set up a live feed from another telescope, this one equipped with an H-alpha filter that narrows the visible spectrum to view details in the sun's chromosphere layer, as well as a live data feed from the ionospheric radar experiment at MIT Haystack next door.&nbsp;</p>
<p>Further afield, some 50 MIT alumni and family members <a href="http://news.mit.edu/2017/qa-richard-binzel-tips-for-observing-solar-eclipse-0815" target="_self">traveled together with EAPS Professor Rick Binzel</a> to Rexburg, Idaho, to experience the solar eclipse within the region of totality — a narrow band across the U.S. where the moon completely blocked out the sun. The location was chosen based on extensive research by Binzel to determine a spot most likely to have favorable weather and clear skies. The MIT group got up early to avoid expected traffic and spent the eclipse on Brigham Young University's Idaho campus. The group, carrying MIT flags and a variety of safe viewing devices, enjoyed the spectacle after hearing expert lectures from Binzel on the science of the eclipse.</p>
<p>Preparations are already underway for the next total solar eclipse across the United States in 2024, for which the path of totality will stretch from Texas to Maine.</p>
Several thousand people gathered at MIT to watch the partial solar eclipse on Aug. 21. Photo: Maia Weinstock/MITSpecial events and guest speakers, Community, EAPS, Alumni/ae, Space, astronomy and planetary science, Haystack Observatory, School of ScienceDanielle Wood joins Media Lab facultyhttps://news.mit.edu/2017/danielle-wood-joins-media-lab-faculty-0828
MIT alumna is establishing a new research group aimed at harnessing space engineering to improve life on Earth.Mon, 28 Aug 2017 09:00:00 -0400MIT Media Labhttps://news.mit.edu/2017/danielle-wood-joins-media-lab-faculty-0828<p>Danielle Wood ’05, SM ’08, PhD ’12 is the Media Lab’s newest assistant professor in the Program in Media Arts and Sciences. She will officially start working at the lab on Jan. 16, 2018, to establish a new research group, called <a href="http://www.media.mit.edu/groups/space-enabled/overview/" target="_blank">Space Enabled</a>. Her mission is to advance justice and development in Earth's complex systems using designs enabled by space.</p>
<p>“Let’s keep striving for the ideal that space really is for the benefit of all humankind,” <a href="https://www.media.mit.edu/videos/beyond-the-cradle-2017-03-12/" target="_blank">Wood said</a> at a Media Lab event in March when she took part in a panel discussion about the future of space research. A scholar of societal development with a background that includes satellite design, systems engineering, and technology policy for the U.S. and emerging nations, Wood added that “space research is just a link in a bigger chain, part of a broad system of technology and art and science and design.” Her passion, she said, has been in designing satellite systems that serve societal needs while integrating new technology.</p>
<p>Growing up in Orlando, where she frequently witnessed space shuttle launches, Wood was inspired by how NASA teams came together to achieve such precise and challenging missions. But she also wanted to find opportunities to serve people directly in her career. Ultimately, that combination of interests led her to study aerospace engineering, policy, and international development. As a doctoral student at MIT, Wood traveled to 15 countries over 10 months as part of in-depth research on new satellite programs in Africa and Asia. The study explained how governments can harness international collaboration to foster domestic capability building and national development.</p>
<p>“Danielle ties space, development, and earth sciences together in a unique and impactful, Media Lab-like way,” says Media Lab Director Joi Ito. He adds that she “fits perfectly into our community like the puzzle piece you’ve been looking for forever.”</p>
<p><strong>Research priorities and plans</strong></p>
<p>In setting up the new group, Space Enabled, Wood plans to reduce barriers to applying space technology for societal benefit. Her research pursues a four-fold cycle that includes observation, explanation, co-design, and evaluation of complex systems that deliver public sector services, using methods from engineering and social science. “I am particularly interested in areas such as environment, health care, education, and law enforcement,” Wood explains. “These public service systems foster justice and societal development when they provide equitable access and high-quality service to consumers across the socioeconomic spectrum.” To that end, her group will partner with communities in the U.S. and abroad on long-term projects to implement new designs enabled by capabilities from space, such as satellite-based earth observation.</p>
<p>Wood’s group will include researchers and staff who bring together “multiple, seemingly unrelated interests. Some of the skill sets relevant to the projects I plan to pursue include engineering, design, technology policy, law, social science, geography, earth science, public health, history, art, and data analytics.” The Space Enabled team will not work in isolation: Wood says she expects to collaborate with other research groups at the Media Lab and also contribute to its <a href="http://www.media.mit.edu/groups/space-exploration/overview/" target="_blank">Space Exploration initiative</a>. &nbsp;&nbsp;</p>
<p>Currently, Wood serves as the applied sciences manager at NASA’s Goddard Space Flight Center, where she focuses on using earth science findings for societal applications, such as food security and water resource management. Previously, she served as special assistant and advisor to NASA’s deputy administrator, and prior to NASA, she worked at the Aerospace Corporation, Johns Hopkins University, and the United Nations Office of Outer Space Affairs.</p>
<p><strong>MIT roots and inspiration</strong></p>
<p>At MIT, Wood earned a PhD in systems engineering, a master's in aerospace engineering, a master's in technology policy, and a bachelor's in aerospace engineering. At the Media Lab’s “<a href="http://news.mit.edu/2017/media-lab-sets-sights-on-space-0314" target="_self">Beyond the Cradle</a>” event in March, Wood said that during her time at the Institute she was inspired by the expansion of space activity around the world and the potential uses of data captured by satellites. “But the question then becomes, how does the average person take advantage of that information? I look forward to co-designing solutions with communities to empower them to use space to make their own lives better. This is important in areas like food security, disaster response, and monitoring the spread of diseases influenced by environmental factors.”</p>
<p>During her time at MIT, Wood was awarded five fellowships, not only from MIT but also from the National Science Foundation, the National Defense Science and Engineering Graduate program, and NASA’s Harriett G. Jenkins Predoctoral Fellowship Program.</p>
<p>Wood’s work has drawn widespread recognition. She has won grants from the Future Space Leaders Foundation (2016) and the National Science Foundation (2013), and she’s received awards from many organizations, including the Global Competitiveness Conference (2015), the International Astronautical Federation (2012) and NASA (2010). Wood has presented her research through many scholarly publications, conferences, and invited talks across Africa, Asia, Europe, Australia, and North America.</p>
<p>Wood says she’s excited to return to MIT with a new perspective shaped by her professional path thus far. “I have worked in government, academia, and the private sector, which gives me an understanding of how each community functions. This experience will help me build strong teams in my future research at the Media Lab.”</p>
Danielle Wood spoke at the Media Lab’s space event, Beyond the Cradle, in March. She will join the faculty full-time in January 2018.Photo: David Silverman PhotographyFaculty, Alumni/ae, Space, astronomy and planetary science, Space exploration, Aeronautical and astronautical engineering, NASA, Earth and atmospheric sciences, Developing countries, Satellites, Media Lab, School of Architecture and Planning, School of Engineering, Engineering Systems, PovertyInvestigating space weather effects of the 2017 solar eclipsehttps://news.mit.edu/2017/mit-haystack-observatory-investigates-space-weather-effects-solar-eclipse-0817
Atmospheric scientists at the MIT Haystack Observatory will study North American eclipse effects on space weather with radar and navigational satellites.Thu, 17 Aug 2017 10:40:01 -0400Haystack Observatoryhttps://news.mit.edu/2017/mit-haystack-observatory-investigates-space-weather-effects-solar-eclipse-0817<p>On Aug. 21, a solar eclipse will occur over the United States. Hotels throughout the 70-mile-wide path of totality from Oregon to South Carolina have been completely booked by amateur astronomers and excited skywatchers. Even outside the path of totality, a partial solar eclipse will take place across the entire continental U.S. Scientists at MIT are taking advantage of this rare event to study its effects on weather in the near-Earth space around our planet, a place directly affected by our nearest star — the sun.</p>
<p>MIT’s Haystack Observatory is <a href="https://eclipse2017.nasa.gov/science-ground" target="_blank">one of several institutions</a>&nbsp;whose ground-based eclipse research has been funded by NASA. A team led by Haystack Assistant Director Phil Erickson will investigate the effects of the eclipse on the Earth’s ionosphere, using the National Science Foundation-supported Millstone Hill incoherent scatter radar facility in Westford, Massachusetts, together with an extensive network of ground-based GPS receivers, National Science Foundation Arecibo Observatory in Puerto Rico, and <a href="https://www.nasa.gov/directorates/heo/scan/services/missions/earth/TIMED.html" target="_blank">NASA's TIMED satellite mission</a>.</p>
<p>Scientists at Haystack will also monitor supplementary GPS signal collection sites within the path of totality to augment existing receivers during the eclipse. These additional GPS receiver sites will collect data at a special, advanced rate before, during, and after the eclipse. Data will be added to a worldwide observation set gathered from the network of GPS and other navigational satellite systems that surround the Earth, providing valuable information on the atmospheric changes that occur during the eclipse.</p>
<p>“The most exciting thing about the eclipse for scientists is that we’ll be able to monitor this event in incredible detail, using a combination of high-precision satellite networks all along the path of totality,” says Anthea Coster, Haystack Observatory assistant director. “The specially equipped receivers we’re placing across the continent will enable us to gather data of unprecedented quality.”</p>
<p>Haystack researchers will study the eclipse’s effects on the ionosphere, the charged part of the Earth’s upper atmosphere that is created daily by solar radiation on the upper neutral atmosphere. Essential communications and navigational satellite systems are located above the ionosphere, and geomagnetic storms have the potential to disrupt these systems as well as our electrical power grids. By studying the effects of the eclipse on the ionosphere, we can learn more about the atmospheric response to solar flares and other space weather events.</p>
<p>During the eclipse the sun will, in effect, turn off and back on very quickly, potentially causing waves called traveling ionospheric disturbances (TIDs). Both hemispheres are affected by such ionospheric events, due to electrical coupling across hemispheres. Research during this eclipse will involve much more precise and better distributed ground-based monitoring tools than ever before, in combination with GPS and other satellite overflights.</p>
<p>Haystack will <a href="http://www.haystack.mit.edu/eclipse.html" target="_blank">livestream changes in the ionosphere</a> as seen by the Millstone Hill radar data on the day of the eclipse, along with a <a href="https://www.youtube.com/channel/UCTMFI03t3zJQzkHPdVo5d-A" target="_blank">live optical feed</a> of the sun’s disk from MIT Wallace Observatory. Haystack and Wallace are also co-hosting an eclipse-watching event in Westford. The event is currently at maximum capacity, but Cambridge-based eclipse watchers can participate in the <a href="https://eapsweb.mit.edu/solar-eclipse-2017" target="_blank">on-campus event</a> hosted by the Department of Earth, Atmospheric and Planetary Sciences or other local viewing events.</p>
<p>Please note: Eye protection is essential for all eclipse viewers, as well as for your camera lens. Never look directly at the sun during the eclipse, and remind children of the danger! If you are using your own solar glasses, be sure to first consult the <a href="https://eclipse.aas.org/resources/solar-filters" target="_blank">American Astronomical Society list of reputable vendors</a> of solar viewing products.</p>
The Millstone Hill radar facility at MIT Haystack Observatory in Westford, MassachusettsImage: Shun-Rong Zhang/MIT Haystack ObservatoryResearch, Space, astronomy and planetary science, Radar, Haystack Observatory, Earth and atmospheric sciences, NASA, Astronomy, National Science Foundation (NSF)Q&amp;A: Richard Binzel on tips for observing the 2017 solar eclipsehttps://news.mit.edu/2017/qa-richard-binzel-tips-for-observing-solar-eclipse-0815
Whether you&#039;ll be in the path of totality on Aug. 21 or anywhere else in North America, you should be able to view the eclipse.Tue, 15 Aug 2017 13:30:09 -0400MIT Alumni Associationhttps://news.mit.edu/2017/qa-richard-binzel-tips-for-observing-solar-eclipse-0815<p><em>It has been nearly a century since a total solar eclipse traversed coast-to-coast across the continental United States. Everyone in North America will have a view of the moon blocking at least part of the sun, in what's known as a partial solar eclipse (depending on local cloud cover, of course). But the spectacle of a lifetime is seeing the sun completely, 100 percent eclipsed by the moon. A narrow “path of totality” will stretch from Salem, Oregon on the West Coast to Lincoln, Nebraska, to St. Louis, Missouri, to Charleston, South Carolina on the East Coast. In these locations, even cloudy skies won't keep you from experiencing the magic of a total eclipse. At and around MIT, the moon will take its first “bite” out of the sun at 1:28 p.m. EDT, max out at 63 percent coverage at 2:46 p.m., and take its last bite out of the sun at 3:59 p.m.</em></p>
<p><em>Eclipse enthusiast Richard P. Binzel, a professor of earth, atmospheric, and planetary sciences at MIT, recently gave the MIT Alumni Association some tips on viewing 2017's spectacular eclipse. Binzel will be leading an&nbsp;Alumni Association Travel Program <a href="https://alum.mit.edu/travel/travel-schedule-2017/idaho-2017" target="_blank">trip to Idaho</a> to view the totality in person. He joins a number of leaders at and around MIT who will be helping individuals observe and enjoy the eclipse. On MIT campus, there will be a <a href="https://eapsweb.mit.edu/solar-eclipse-2017" target="_blank">solar viewing party</a> on the Kresge Oval, free and open to the public. A special <a href="http://eapsweb.mit.edu/solar-eclipse-viewing-mit-wallace-observatory" target="_blank">viewing event at MIT's Wallace Observatory</a> will also take place. </em></p>
<p><strong>Q: </strong>What’s the difference between seeing a partial versus total solar eclipse?</p>
<p><strong>A: </strong>A total solar exlipse is a million times more spectacular than a partial eclipse. That is not hyperbole, it is precisely the factor by which the brightness of the sun and the sky changes (in an instant!) at the moment of transition from partial eclipse to total eclipse. At the moment total eclipse begins, the last sliver of the sun’s disk becomes hidden behind the edge of the moon. For the duration of the total eclipse — about two minutes — nightfall is all around you even though it is midday. Stars appear in the sky! All that is visible of the sun is its eerie outer glowing halo called the corona. Then just as instantly, the total eclipse ends and daylight dramatically returns as the moon continues its motion, allowing the sun’s disk to re-emerge.</p>
<p><strong>Q:</strong> Where will this year's total solar eclipse take place?</p>
<p><b>A: </b>NASA's <a href="https://eclipse2017.nasa.gov/sites/default/files/interactive_map/index.html" rel="external" target="_blank">interactive map</a> lets you zoom in exactly on where is the closest or most convenient place for you to travel to be in the path of the total eclipse on August 21.</p>
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<p><strong>Q:</strong> Even those not in the path of totality will be able to view the eclipse. So what should viewers do about eye safety?</p>
<p><b><b>A:</b> </b>Everyone talks about eye safety during solar eclipses. It is not because the sun’s light is any more dangerous during an eclipse. (It’s not!) The issue is that eclipses are a time when we are all interested to stare at the sun, and it is never safe to stare at the sun without proper protection. So no matter where you will be on August 21, order a pair of special “eclipse glasses.” They are relatively inexpensive and are readily available, while supplies last. Regular sunglasses are not sufficiently safe for solar eclipse viewing. It is perfectly safe to be pursuing normal activities outside during an eclipse without eclipse glasses. Just have those glasses handy so that you can take a moment to stare at the sun and check out the workings of the cosmos! If you want to use binoculars or a telephoto lens, proper protection is required over the front of those lenses too!</p>
<p><strong>Q: </strong>Where outside is a good place to watch?</p>
<p><b>A: </b>Any place outside that you can see the sun itself is a place where you can view the eclipse. It can be a yard, a driveway, a parking lot, a baseball field, etc. Any place where the sun is not blocked by trees or buildings is a place where you can view the eclipse. In places where a total solar eclipse is visible, even if the weather is cloudy and you can’t see the sun at all, you will notice that everything is unusually dark as you get to the time of maximum eclipse. In fact, you may see streetlights switching on in response to the darkening skies.</p>
<p><strong>Q: </strong>What time is the eclipse, and what will I see?</p>
<p><b>A:</b> Everything happens on Monday, August 21, starting in the morning on the West Coast through early afternoon on the East Coast as the moon’s shadow sweeps from west to east. For exact details on the timing of events, click on your viewing location using NASA's <a href="https://eclipse2017.nasa.gov/sites/default/files/interactive_map/index.html" rel="external" target="_blank">interactive map</a>.<b> </b>If you are in the path of totality, and the sun is completely covered by the moon, this is the only exception when you can stare at the sun without eclipse glasses. That’s because the sun’s bright disk is covered and you will see only the faint outer halo of the sun. That halo, called the solar corona, will be studied intensively by scientists during the fleeting minutes of totality.<b> </b>If you decide to travel to be within the “path of totality” on August 21, good for you! Arrive at your destination at least one day — 24 hours; two days might be even better — in advance as eclipse traffic jams on or before August 21 could be legendary! Some folks may take to the highways to race against the weather as the time of totality approaches. Traffic safety suggests this may not be a good idea. Remember, you will experience the sudden change in darkness even if you find yourself under clouds for the main event.</p>
<p>Watch this <a href="https://www.theguardian.com/science/video/2012/nov/14/solar-eclipse-australia-video" rel="external" target="_blank">video example</a> of the dramatic change from a partial eclipse to a total eclipse, demonstrating why you should journey into the path of totality. You can also check out a <a href="https://svs.gsfc.nasa.gov/4314" rel="external" target="_blank">NASA visualization</a> for how and why the moon’s shadow will move across the U.S. on August 21.</p>
<p><em>A version of this article was originally published by the MIT Alumni Association.</em></p>
A map of the United States shows the path of totality for the August 21 solar eclipse.Image: Ernie Wright/Goddard Space Flight CenterSpace, astronomy and planetary science, Faculty, EAPS, Special events and guest speakers, School of ScienceTraining students&#039; eyes on the skieshttps://news.mit.edu/2017/training-students-eyes-on-skies-mit-astronomy-camp-0810
MIT hosts Astronomy Training Camp for student-run national astronomy team.Thu, 10 Aug 2017 13:50:01 -0400Helen Hill | EAPShttps://news.mit.edu/2017/training-students-eyes-on-skies-mit-astronomy-camp-0810<p>During the last week in July, 15 high school students from across the U.S. traveled to MIT to participate in the second annual MIT Astronomy Training Camp (ATC), in support of the USA Astronomy and Astrophysics Olympiad (<a href="http://usaaao.org/" target="_blank">USAAAO</a>), the student-run national astronomy team.</p>
<p>The group included four of the five&nbsp;USAAAO&nbsp;2017 team members, plus 11 others participating in the camp out of a curiosity about astronomy — and to perhaps land a spot on next year's team.</p>
<p>USAAAO team members study astronomical theory throughout the year on their own and through weekly online group chats. The weeklong residential training camp supplements this self-study by focusing on topics that are difficult to learn on one's own: how to set up and use a telescope, how to recognize constellations, and how to analyze astronomical data.</p>
<p>The ATC is run by <a href="http://eapsweb.mit.edu/people/asbosh" target="_blank">Amanda Bosh</a>&nbsp;a senior lecturer in MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS). "I'm so impressed by the incredible dedication of the student organizers of the USAAAO. They formed a national team on their own, and previous team members have been working with new team members to help prepare for the international competition. For the International Olympiad on Astronomy and Astrophysics, many countries support their teams on a national level, with years of assistance and training. At MIT, we're helping out by providing resources in the form of telescopes to use for practice, a space for students to come together and learn as a group, and assistance from myself and MIT undergraduates."</p>
<p>Classes at the camp were taught by Bosh and by Harvard University graduate students Roxana Pop and Ioana Zelko. Also participating were MIT undergraduates Evan Tey, Cecilia Siqueiros, Max Kessler, and Viban Gonzalez as well as Anicia Arredondo and Bryan Brzycki. Chris Peterson, senior assistant director with MIT’s Department of Undergraduate Education, helped with logistics.</p>
<p>ATC activities included an opening reception in the Ida Green Lounge of MIT Building 54; a tour of campus with Ho Chit Siu SM '15, an EAPS graduate who is currently a PhD candidate aeronautics and astronautics; night sky observing on the rooftop observing platform used by <a href="https://www.youtube.com/watch?v=UEWskDclsIc" target="_blank">Observe@MIT</a>&nbsp;(on Building 37); a trip to the Wallace Astrophysical Observatory, and a field trip to the Harvard Museum to view an exhibit on scientific instruments.</p>
<p>A visit to the Charles Hayden Planetarium at the Museum of Science in Boston was made possible by a special gift to the Astronomy Training Camp from Robert N. Gurnitz '60, SM '61, PhD '66 and his wife, Ellen, who also sponsored last year’s pilot Astronomy Training Camp. Their generous gift allowed the students to have a private session at the planetarium, where Planetarium Coordinator Talia Sepersky had prepared their state-of-the-art Zeiss Starmaster projector to show the night sky as it will appear in Thailand in November (the time and place of the competition). Using laser pointers, the camp participants pointed out constellations, bright stars, and deep sky objects with Sepersky blinking on the constellation lines and boundaries to assist the students in identifying the smaller and fainter stellar groupings.</p>
<p>On Friday, the last full day of camp, the students were treated to in-depth talks on cosmology by MIT Kavli Institute for Astrophysics and Space Research postdoc Paul Torrey, and on exoplanets by EAPS Heising-Simons Fellow Jason Dittmann. Lively conversations on current research followed each presentation.</p>
<p>The camp was clearly a once in a lifetime experience for these students. As one participant put it: “The opportunity to learn and talk with other students who are just as passionate as you is one of the best experiences you can have as a high school student interested in astronomy and astrophysics.”</p>
The path of the International Space Station can be seen from the Observe@MIT rooftop observing platform on Building 37. Participants in the second annual MIT Astronomy Training Camp took to the roof for pointers on night sky observing.Photo: Amanda BoshSpecial events and guest speakers, STEM education, K-12 education, EAPS, Space, astronomy and planetary science, Astronomy, School of ScienceLunar dynamo’s lifetime extended by at least 1 billion yearshttps://news.mit.edu/2017/lunar-dynamo-lifetime-extended-least-1-billion-years-0809
Findings suggest two mechanisms may have powered the moon’s ancient churning, molten core. Wed, 09 Aug 2017 13:59:59 -0400Jennifer Chu | MIT News Officehttps://news.mit.edu/2017/lunar-dynamo-lifetime-extended-least-1-billion-years-0809<p>New evidence from ancient lunar rocks suggests that an active dynamo once churned within the molten metallic core of the moon, generating a magnetic field that lasted at least 1 billion years longer than previously thought. Dynamos are natural generators of magnetic fields around terrestrial bodies, and are powered by&nbsp;the churning of conducting fluids within many stars and planets.</p>
<p>In a paper published today in <em>Science Advances</em>, researchers from MIT and Rutgers University report that a lunar rock collected by NASA’s Apollo 15 mission exhibits signs that it formed 1 to 2.5 billion years ago in the presence of a relatively weak magnetic field of about 5 microtesla. That’s around 10 times weaker than Earth’s current magnetic field but still 1,000 times larger than fields in interplanetary space today.</p>
<p>Several years ago, the same researchers identified 4-billion-year-old lunar rocks that formed under a much stronger field of about 100 microtesla, and they determined that the strength of this field dropped off precipitously around 3 billion years ago. At the time, the researchers were unsure whether the moon’s dynamo — the related magnetic field — died out shortly thereafter or lingered in a weakened state before dissipating completely.</p>
<p>The results reported today support the latter scenario: After the moon’s magnetic field dwindled, it nonetheless persisted for at least another billion years, existing for a total of at least 2 billion years.</p>
<p>Study co-author Benjamin Weiss, professor of planetary sciences in MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS), says this new extended lifetime helps to pinpoint the phenomena that powered the moon’s dynamo. Specifically, the results raise the possibility of two different mechanisms — one that may have driven an earlier, much stronger dynamo, and a second that kept the moon’s core simmering at a much slower boil toward the end of its lifetime.</p>
<p>“The concept of a planetary magnetic field produced by moving liquid metal is an idea that is really only a few decades old,” Weiss says. “What powers this motion on Earth and other bodies, particularly on the moon, is not well-understood. We can figure this out by knowing the lifetime of the lunar dynamo.”</p>
<p>Weiss’ co-authors are lead author Sonia Tikoo, a former MIT graduate student who is now an assistant professor at Rutgers; David Shuster of the University of California at Berkeley; Clément Suavet and Huapei Wang of EAPS; and Timothy Grove, the R.R. Schrock Professor of Geology and associate head of EAPS.</p>
<p><strong>Apollo’s glassy recorders</strong></p>
<p>Since NASA’s Apollo astronauts brought back samples from the lunar surface, scientists have found some of these rocks to be accurate “recorders” of the moon’s ancient magnetic field. Such rocks contain thousands of tiny grains that, like compass needles, aligned in the direction of ancient fields when the rocks crystallized eons ago. Such grains can give scientists a measure of the moon’s ancient field strength.</p>
<p>Until recently, Weiss and others had been unable to find samples much younger than 3.2 billion years old that could accurately record magnetic fields. As a result, they had only been able to gauge the strength of the moon’s magnetic field between 3.2 and 4.2 billion years ago.</p>
<p>“The problem is, there are very few lunar rocks that are younger than about 3 billion years old, because right around then, the moon cooled off, volcanism largely ceased and, along with it, formation of new igneous rocks on the lunar surface,” Weiss explains. “So there were no young samples we could measure to see if there was a field after 3 billion years.”</p>
<p>There is, however, a small class of rocks brought back from the Apollo missions that formed not from ancient lunar eruptions but from asteroid impacts later in the moon’s history. These rocks melted from the heat of such impacts and recrystallized in orientations determined by the moon’s magnetic field.</p>
<p>Weiss and his colleagues analyzed one such rock, known as Apollo 15 sample 15498, which was originally collected on Aug. 1, 1971, from the southern rim of the moon’s Dune Crater. The sample is a mix of minerals and rock fragments, welded together by a glassy matrix, the grains of which preserve records of the moon’s magnetic field at the time the rock was assembled.</p>
<p>“We found that this glassy material that welds things together has excellent magnetic recording properties,” Weiss says.</p>
<p><strong>Baking rocks</strong></p>
<p>The team determined that the rock sample was about 1 to 2.5 billion years old — much younger than the samples they previously analyzed. They developed a technique to decipher the ancient magnetic field recorded in the rock’s glassy matrix by first measuring the rock’s natural magnetic properties using a very sensitive magnetometer.</p>
<p>They then exposed the rock to a known magnetic field in the lab, and heated the rock to close to the extreme temperatures in which it originally formed. They measured how the rock’s magnetization changed as they increased the surrounding temperature.</p>
<p>“You see how magnetized it gets from getting heated in that known magnetic field, then you compare that field to the natural magnetic field you measured beforehand, and from that you can figure out what the ancient field strength was,” Weiss explains.</p>
<p>The researchers did have to make one significant adjustment to the experiment to better simulate the original lunar environment, and in particular, its atmosphere. While the Earth’s atmosphere contains around 20 percent oxygen, the moon has only imperceptible traces of the gas. In collaboration with Grove, Suavet built a customized, oxygen-deprived oven in which to heat the rocks, preventing them from rusting while at the same time simulating the oxygen-free environment in which the rocks were originally magnetized.</p>
<p>“In this way, we finally have gotten an accurate measurement of the lunar field,” Weiss says.</p>
<p><strong>From ice cream makers to lava lamps</strong></p>
<p>From their experiments, the researchers determined that, around 1 to 2.5 billion years ago, the moon harbored a relatively weak magnetic field, with a strength of about 5 microtesla — two orders of magnitude weaker than the moon’s field around 3 to 4 billion years ago. Such a dramatic dip suggests to Weiss and his colleagues that the moon’s dynamo may have been driven by two distinct mechanisms.</p>
<p>Scientists have proposed that the moon’s dynamo may have been powered by the&nbsp; Earth’s gravitational pull. Early in its history, the moon orbited much closer to the Earth, and the Earth’s gravity, in such close proximity, may have been strong enough to pull on and rotate the rocky exterior of the moon. The moon’s liquid center may have been dragged along with the moon’s outer shell, generating a very strong magnetic field in the process.</p>
<p>It’s thought that the moon may have moved sufficiently far away from the Earth by about 3 billion years ago, such that the power available for the dynamo by this mechanism became insufficient. This happens to be right around the time the moon’s magnetic field strength dropped. A different mechanism may have then kicked in to sustain this weakened field. As the moon moved away from the Earth, its core likely sustained a low boil via a slow process of cooling over at least 1 billion years.</p>
<p>“As the moon cools, its core acts like a lava lamp — low-density stuff rises because it’s hot or because its composition is different from that of the surrounding fluid,” Weiss says. “That’s how we think the Earth’s dynamo works, and that’s what we suggest the late lunar dynamo was doing as well.”</p>
<p>The researchers are planning to analyze even younger lunar rocks to determine when the dynamo died off completely.</p>
<p>“Today the moon’s field is essentially zero,” Weiss says. “And we now know it turned off somewhere between the formation of this rock and today.”</p>
<p>This research was supported, in part, by NASA.</p>
New measurements of lunar rocks have demonstrated that the ancient moon generated a dynamo magnetic field in its liquid metallic core (innermost red shell). The results raise the possibility of two different mechanisms — one that may have driven an earlier, much stronger dynamo, and a second that kept the moon’s core simmering at a much slower boil toward the end of its lifetime. Image: Hernán Cañellas (provided by Benjamin Weiss)Moon, Astronomy, Astrophysics, EAPS, Planetary science, Research, School of Science, Geology, NASA, Space, astronomy and planetary scienceTiny terahertz laser could be used for imaging, chemical detectionhttps://news.mit.edu/2017/tiny-terahertz-laser-imaging-chemical-detection-0808
New design boosts the power output of the best-performing chip-scale terahertz laser by 80 percent.Tue, 08 Aug 2017 13:30:00 -0400Larry Hardesty | MIT News Officehttps://news.mit.edu/2017/tiny-terahertz-laser-imaging-chemical-detection-0808<p>Terahertz radiation — the band of the electromagnetic spectrum between microwaves and visible light — has promising applications in medical and industrial imaging and chemical detection, among <a href="http://news.mit.edu/2016/computational-imaging-method-reads-closed-books-0909">other</a> <a href="http://news.mit.edu/2014/terahertz-imaging-cheap-0505">uses</a>.</p>
<p>But many of those applications depend on small, power-efficient sources of terahertz rays, and the standard method for producing them involves a bulky, power-hungry, tabletop device.</p>
<p>For more than 20 years, Qing Hu, a distinguished professor of electrical engineering and computer science at MIT, and his group have been working on sources of terahertz radiation that can be etched onto microchips. In the latest issue of <em>Nature Photonics</em>, members of Hu’s group and colleagues at Sandia National Laboratories and the University of Toronto describe a novel design that boosts the power output of chip-mounted terahertz lasers by 80 percent.</p>
<p>As the best-performing chip-mounted terahertz source yet reported, the researchers’ device has been selected by NASA to provide terahertz emission for its Galactic/Extragalactic ULDB Spectroscopic Terahertz Observatory (GUSTO) mission. The mission is intended to determine the composition of the interstellar medium, or the matter that fills the space between stars, and it’s using terahertz rays because they’re uniquely well-suited to spectroscopic measurement of oxygen concentrations. Because the mission will deploy instrument-laden balloons to the Earth’s upper atmosphere, the terahertz emitter needs to be lightweight.</p>
<p>The researchers’ design is a new variation on a device called a quantum cascade laser with distributed feedback. “We started with this because it was the best out there,” says Ali Khalatpour, a graduate student in electrical engineering and computer science and first author on the paper. “It has the optimum performance for terahertz.”</p>
<p>Until now, however, the device has had a major drawback, which is that it naturally emits radiation in two opposed directions. Since most applications of terahertz radiation require directed light, that means that the device squanders half of its energy output. Khalatpour and his colleagues found a way to redirect 80 percent of the light that usually exits the back of the laser, so that it travels in the desired direction.</p>
<p>As Khalatpour explains, the researchers’ design is not tied to any particular “gain medium,” or <a href="http://news.mit.edu/2016/speedy-terahertz-based-system-could-detect-explosives-0520">combination of materials</a> in the body of the laser.</p>
<p>“If we come up with a better gain medium, we can double its output power, too,” Khalatpour says. “We increased power without designing a new active medium, which is pretty hard. Usually, even a 10 percent increase requires a lot of work in every aspect of the design.”</p>
<p><strong>Big waves</strong></p>
<p>In fact, bidirectional emission, or emission of light in opposed directions, is a common feature of many laser designs. With conventional lasers, however, it’s easily remedied by putting a mirror over one end of the laser.</p>
<p>But the wavelength of terahertz radiation is so long, and the researchers’ new lasers — known as photonic wire lasers — are so small, that much of the electromagnetic wave traveling the laser’s length actually lies outside the laser’s body. A mirror at one end of the laser would reflect back a tiny fraction of the wave’s total energy.</p>
<p>Khalatpour and his colleagues’ solution to this problem exploits a peculiarity of the tiny laser’s design. A quantum cascade laser consists of a long rectangular ridge called a waveguide. In the waveguide, materials are arranged so that the application of an electric field induces an electromagnetic wave along the length of the waveguide.</p>
<p>This wave, however, is what’s called a “standing wave.” If an electromagnetic wave can be thought of as a regular up-and-down squiggle, then the wave reflects back and forth in the waveguide in such a way that the crests and troughs of the reflections perfectly coincide with those of the waves moving in the opposite direction. A standing wave is essentially inert and will not radiate out of the waveguide.</p>
<p>So Hu’s group cuts regularly spaced slits into the waveguide, which allow terahertz rays to radiate out. “Imagine that you have a pipe, and you make a hole, and the water gets out,” Khalatpour says. The slits are spaced so that the waves they emit reinforce each other — their crests coincide — only along the axis of the waveguide. At more oblique angles from the waveguide, they cancel each other out.</p>
<p><strong>Breaking symmetry</strong></p>
<p>In the new work, Khalatpour and his coauthors — Hu, John Reno of Sandia, and Nazir Kherani, a professor of materials science at the University of Toronto — simply put reflectors behind each of the holes in the waveguide, a step that can be seamlessly incorporated into the manufacturing process that produces the waveguide itself.</p>
<p>The reflectors are wider than the waveguide, and they’re spaced so that the radiation they reflect will reinforce the terahertz wave in one direction but cancel it out in the other. Some of the terahertz wave that lies outside the waveguide still makes it around the reflectors, but 80 percent of the energy that would have exited the waveguide in the wrong direction is now redirected the other way.</p>
<p>“They have a particular type of terahertz quantum cascade laser, known as a third-order distributed-feedback laser, and this right now is one of the best ways of generating a high-quality output beam, which you need to be able to use the power that you’re generating, in combination with a single frequency of laser operation, which is also desirable for spectroscopy,” says Ben Williams, an associate professor of electrical and computer engineering at the University of California at Los Angeles. “This has been one of the most useful and popular ways to do this for maybe the past five, six years. But one of the problems is that in all the previous structures that either Qing’s group or other groups have done, the energy from the laser is going out in two directions, both the forward direction and the backward direction.”</p>
<p>“It’s very difficult to generate this terahertz power, and then once you do, you’re throwing away half of it, so that’s not very good,” Williams says. “They’ve come up with a very elegant scheme to essentially force much more of the power to go in the forward direction. And it still has a good, high-quality beam, so it really opens the door to much more complicated antenna engineering to enhance the performance of these lasers.”</p>
<p>The new work was funded by NASA, the National Science Foundation, and the U.S. Department of Energy.</p>
A new technique boosts the power output of tiny, chip-mounted terahertz lasers by 88 percent.
Image: Demin Liu/MolgraphicsResearch, School of Engineering, Electrical Engineering & Computer Science (eecs), NASA, National Science Foundation (NSF), Research Laboratory of Electronics, Department of Energy (DoE)TESS mission to discover new planets moves toward launchhttps://news.mit.edu/2017/tess-mission-discover-new-planets-moves-toward-launch-0804
Satellite’s cameras have been delivered by MIT researchers and passed NASA inspection.Fri, 04 Aug 2017 16:30:00 -0400Helen Knight | MIT Kavli Institute for Astrophysics and Space Researchhttps://news.mit.edu/2017/tess-mission-discover-new-planets-moves-toward-launch-0804<p>A NASA mission designed to explore the stars in search of planets outside of our solar system is a step closer to launch, now that its four cameras have been completed by researchers at MIT.</p>
<p>The <a href="https://tess.gsfc.nasa.gov/">Transiting Exoplanet Survey Satellite</a> (TESS), due to launch in 2018, will travel through space, identifying more than 20,000 extrasolar planets. These will range from Earth-sized planets to much larger gas giants. TESS is expected to catalog a sample of around 500 Earth-sized and “super Earth” planets, or those with radii less than twice that of Earth. It will detect small rock-and-ice planets orbiting a diverse range of stars, including rocky worlds in the habitable zones of their host stars.</p>
<p>“The scientific community is eagerly awaiting the launch of TESS and the first data release in 2018,” says Sara Seager, the Class of 1941 Professor of Planetary Sciences at MIT and deputy lead of the TESS Science Office.</p>
<p>During its two-year mission, TESS, which is being led by MIT and managed by NASA’s Goddard Space Flight Center, will monitor the brightness of more than 200,000 stars. It will search for temporary drops in brightness caused by an exoplanet passing in front of its host star, as viewed from Earth.</p>
<p>The satellite’s four cameras, developed by researchers at MIT’s Kavli Institute for Astrophysics and Space Research and the MIT Lincoln Laboratory, are equipped with large-aperture wide-angle lenses designed to survey the entire sky.</p>
<p>Each camera consists of a lens assembly containing seven optical elements and a detector with four charge-coupled device (CCD) sensor chips. The overall process of designing, fabricating, and testing the cameras at MIT has taken four years to complete.</p>
<p>The cameras were recently delivered to Dulles, Virginia-based aerospace company Orbital ATK, where they will be integrated onto the satellite. The four cameras have been mounted onto the camera plate, and successful operation with the flight computer has been demonstrated.</p>
<p>The instruments have just been inspected by NASA and a group of independent technical experts, as part of a formal Systems Integration Review of all TESS components, which they passed successfully.</p>
<p>Each of the four cameras has a field of view that is more than five times greater than that of the camera flown on the earlier planet-hunting <a href="https://www.nasa.gov/mission_pages/kepler/overview/index.html">Kepler space observatory mission</a>, according to TESS Principal Investigator George Ricker, senior research scientist at the MIT Kavli Institute.</p>
<p>“The TESS four-camera ensemble instantaneously views a section of sky that is more than 20 times greater than that for the Kepler mission,” Ricker says. “The instantaneous field of view of the TESS cameras, combined with their area and detector sensitivity, is unprecedented in a space mission.”</p>
<p>A complication found in very fast wide-angle lenses, such as those in the TESS cameras, is that the image sharpness varies over the field of view, and there is no single focus, as found in more conventional cameras. Furthermore, the imaging properties change as the temperature of the cameras changes.</p>
<p>The MIT TESS team has subjected the cameras to extended, rigorous testing in conditions designed to replicate the environment they will be subjected to in space. These tests demonstrate that the cameras perform as expected, but with a small shift in focus relative to that predicted by models. This shift results in simulated stellar images in the center of the field appearing sharper than expected, while images at the edges of the field are somewhat less sharp. However, after independently studying the effects of this shift, researchers on the MIT TESS team and at NASA both concluded that the mission will readily achieve all of its scientific goals.</p>
<p>TESS relies on its ability to sense minute changes in stellar brightness to detect planets passing across them. The data processing is designed to correct for the variations in image sharpness over the field for most of the stars, and it will produce a record of brightness over time for every star being monitored, according to Jacqueline Hewitt, director of the MIT Kavli Institute.</p>
<p>The MIT TESS team will continue to carry out long-term ground tests on a spare flight camera to ensure that their in-orbit performance is well understood.</p>
<p>Following its launch next year, TESS will divide the sky into 26 “stitched” sections and will point its cameras at each of these in turn for 27 days. It will explore the Southern Hemisphere in the first year of its mission, and the Northern Hemisphere in its second year.</p>
<p>“TESS is classed by NASA as an Explorer mission with very focused scientific goals,” Hewitt says. “It was designed to find exoplanets that are nearby and orbiting bright stars, so we can study them in great detail.”</p>
<p>The data produced by the cameras will first be processed by the spacecraft’s on-board computer. They will then be transmitted to Earth every two weeks via the NASA Deep Space Network and immediately forwarded to the TESS Payload Operations Center at MIT.</p>
<p>The TESS Science Center, which will analyze the science data produced by the spacecraft, includes researchers from MIT's Department of Physics, Department of Earth, Atmospheric and Planetary Sciences, and the Kavli Institute, as well as the Harvard-Smithsonian Center for Astrophysics, and the NASA Ames Research Center.</p>
Engineers test one of the TESS cameras at the Kavli Institute lab.
Courtesy of the Kavli InstituteTESS, Research, Astronomy, Space exploration, Exoplanets, Satellites, space, space, astronomy, and planetary science, Kavli Institute, Lincoln Laboratory, Physics, EAPS, School of Science, NASAMIT Haystack Observatory&#039;s John Foster named AGU Fellowhttps://news.mit.edu/2017/mit-haystack-observatory-john-foster-named-agu-fellow-0728
Distinguished atmospheric scientist recognized for lifetime of accomplishments.Fri, 28 Jul 2017 17:35:01 -0400Haystack Observatoryhttps://news.mit.edu/2017/mit-haystack-observatory-john-foster-named-agu-fellow-0728<p>John C. Foster, principal research scientist at MIT's Haystack Observatory, has been awarded AGU Fellow status from the American Geophysical Union for 2017. The AGU elects a small group of members to become fellows each year in honor of their scientific leadership and research excellence. Recipients are AGU members who have fundamentally advanced research in their fields of geophysics.</p>
<p>"AGU Fellows are recognized for their scientific eminence in the Earth and space sciences. Their breadth of interests and the scope of their contributions are remarkable and often groundbreaking," the <a href="https://eos.org/agu-news/2017-class-of-agu-fellows-announced" target="_blank">announcement</a> read. "They have expanded our understanding of the Earth and space sciences, from volcanic processes, solar cycles, and deep-sea microbiology to the variability of our climate and so much more. Only 0.1 percent of AGU membership receives this recognition in any given year."</p>
<p>A group of space science colleagues nominated Foster for this award, citing his visionary leadership in space physics research, including transformative insights and work in magnetosphere-plasmasphere-ionosphere coupling, ionospheric storm response, and radiation belt dynamics. A large portion of Foster’s research has been done with ground and space-based observational techniques, including incoherent scatter radar and satellite-borne instruments, using these powerful tools for investigations of the physics of the upper atmosphere and Earth's highly energetic radiation belts. He is an expert in the analysis of data from ionospheric radars at Haystack's Millstone Hill and other facilities. Foster also has been extensively involved in international scientific collaboration with colleagues in China, Ukraine, and Russia.</p>
<p>"John’s excellence and sharp observational eye continues to lead the field in applications of multiple observational points of view from both ground and space remote sensors, creating new insights on the workings of the complicated Sun-Earth system and its dynamics," says Phil Erickson, assistant director at Haystack Observatory. "He is truly outstanding at seeing connections in phenomena that have previously been studied only in isolation."</p>
<p>Broad interests in space science continue today to lead Foster towards innovative and far reaching insights within the vitally important study of cross-scale and cross-disciplinary coupling processes in Earth’s near-space environment. He is an innovator in the application of high-power ionospheric radar systems to the study of plasmas and instabilities in the terrestrial mid-latitude ionosphere.</p>
<p>Foster’s work has taken place across multiple institutions in a career that has lasted more than four decades. After receiving his PhD in physics from the University of Maryland at College Park in 1973, he worked at a number of institutions, including the National Research Council of Canada and Utah State University. In 1983, former Haystack director John Evans recruited Foster to lead its internationally known atmospheric science program. He led this group for more than 30 years, maintaining and significantly growing the scientific and technical staff throughout this time period. He was appointed assistant director of Haystack in 1983 and promoted to principal research scientist in 1988, achieving associate Haystack director status in 1995. Throughout his career, Foster has dedicated much time and effort to mentoring a large number of younger space scientists.</p>
<p>Even beyond this large body of prior work, Foster continues his extensive publication record and a brisk collaboratory pace of fundamental and unique discoveries in space science. His most recent work using data from the twin <a href="https://www.nasa.gov/van-allen-probes" target="_blank">NASA Van Allen Probes spacecraft</a> was <a href="http://onlinelibrary.wiley.com/doi/10.1002/2016JA023429/full" target="_blank">published earlier this year</a> in the AGU's <em>Journal of Geophysical Research Space Physics</em>. The study provides an example of Foster’s innovative observational approach, as he and several colleagues analyzed the nonlinear interactions of ultrarelativistic electrons and very low frequency waves to advance understanding of rapid variations in Earth's outer radiation belt.</p>
John Foster is a senior research scientist at the Haystack Observatory.Photo: Nancy Wolfe KotaryAwards, honors and fellowships, Staff, Haystack Observatory, Physics, Earth and atmospheric sciences, Space, astronomy and planetary scienceExploring an unusual metal asteroidhttps://news.mit.edu/2017/nasa-psyche-mission-lead-lindy-elkins-tanton-exploring-metal-asteroid-0726
Alumna and former MIT professor Lindy Elkins-Tanton is working with MIT faculty in her role as principal investigator for NASA&#039;s upcoming Psyche mission.Tue, 25 Jul 2017 23:59:59 -0400Alice Waugh | MIT Technology Review | MIT Alumni Associationhttps://news.mit.edu/2017/nasa-psyche-mission-lead-lindy-elkins-tanton-exploring-metal-asteroid-0726<p>Lindy Elkins-Tanton ’87, SM ’87, PhD ’02 is reaching for the stars — literally. She is the principal investigator for Psyche, a NASA mission that will explore an unusual metal asteroid known as 16 Psyche.</p>
<p>The mission does not launch until 2023, but preparations have begun in collaboration with faculty in the Department of Earth, Atmospheric and Planetary Sciences (EAPS). Professors Benjamin Weiss and Maria Zuber, who also serves as MIT's vice president for research, wrote a paper about the asteroid with Elkins­-Tanton that was the basis for the team’s selection for NASA’s Discovery Program. MIT Professor Richard Binzel is also a team member.</p>
<p>At MIT, Elkins-Tanton earned BS and MS degrees in geology and geochemistry with a concentration on how planets form. Then she detoured from academia to the business world before becoming a college lecturer in mathematics in 1995.</p>
<p>“I realized that in academia, you have this incredible privilege of always being able to ask a harder, bigger question, so you never get bored, and you have the opportunity to inspire students to do more in their lives,” says Elkins-Tanton. She returned to MIT to earn a PhD in geology and geophysics, and for the next decade after completing that degree, she taught, first at Brown University and then at MIT as an EAPS faculty member.</p>
<p>Since 2014, Elkins-­Tanton has been professor and director of the School of Earth and Space Exploration at Arizona State University. She has been revamping the undergraduate curriculum to give it more of an MIT flavor, bringing current research into the classroom and having students tackle real-world problems. This approach has helped her transmit excitement about the field to her students.</p>
<p>Elkins-Tanton also draws on business skills that she says are quite useful for scientific collaboration: negotiating, making a compelling pitch, and knowing how to build a team that works well. She is applying those skills, along with her management and leadership experience, as the second woman to lead a NASA mission to a major solar system body (after Zuber, who was principal investigator of the Gravity Recovery and Interior Laboratory, or GRAIL, mission).</p>
<p>Psyche represents a compelling target for study because scientists theorize that it was an ordinary asteroid until violent collisions with other objects blasted away most of its outer rock, exposing its metallic core. This core, the first to be studied, could yield insights into the metal interior of rocky planets in the solar system.</p>
<p>“We have no idea what a metal body looks like. The one thing I can be sure of is that it will surprise us,” Elkins-Tanton says. “I love this stuff — there are new discoveries every day.”</p>
<p><em>A version of this article originally appeared in the <a href="https://www.technologyreview.com/mit-news/2017/07/" target="_blank">July/August&nbsp;2017 issue</a></em><em>&nbsp;of&nbsp;</em>MIT Technology Review<em>.</em></p>
As principal investigator of the Psyche mission, Lindy Elkins-Tanton '87, SM ’87, PhD ’02 is just the second woman to lead a NASA spacecraft mission to a planetary body. The first was her former MIT colleague, Vice President for Research Maria Zuber.Photo: Arizona State UniversitySpace, astronomy and planetary science, NASA, Satellites, Asteroids, EAPS, Physics, Alumni/ae, Women in STEM, School of ScienceNew insights into the early universe’s galaxy clustershttps://news.mit.edu/2017/mit-kavli-scientists-gain-new-insights-early-universe-galaxy-clusters-0725
MIT Kavli Institute scientists help conduct one of the largest-ever studies of molecular gas in distant galaxy clusters.Tue, 25 Jul 2017 15:35:01 -0400MIT Kavli Institute for Astrophysics and Space Researchhttps://news.mit.edu/2017/mit-kavli-scientists-gain-new-insights-early-universe-galaxy-clusters-0725<p>Molecular gas is the raw material which fuels star formation throughout the universe. Now, using the revolutionary Atacama Large Millimeter Array (ALMA) telescope, an international team of scientists has conducted one of the largest studies of molecular gas in distant galaxy clusters — rare conglomerations containing hundreds of galaxies, trillions of stars, and dark matter. &nbsp;</p>
<p>Scientists&nbsp;from the&nbsp;Spitzer Adaptation of the Red-sequence Cluster Survey (<a href="http://faculty.ucr.edu/~gillianw/SpARCS/" target="_blank">SpARCS</a>) collaboration&nbsp;observed the&nbsp;galaxies within these distant clusters as they were when the universe was only 4 billion years old. They found that they harbor larger molecular gas reservoirs compared to galaxies in found in more typical isolated environments with fewer galaxy neighbors, known as field galaxies.</p>
<p>“We expected to find molecular gas deficiencies in these cluster galaxies compared to the field,” says&nbsp;lead author Allison Noble, a postdoc at the MIT Kavli Institute for Astrophysics and Space Research.&nbsp;“Galaxies in nearby clusters are dead, lacking star formation activity and with little to no molecular gas.&nbsp;In these distant clusters, we are instead detecting gas-rich galaxies, but their star formation rates are on par with field galaxies.”&nbsp;</p>
<p>The results were <a href="http://iopscience.iop.org/article/10.3847/2041-8213/aa77f3/pdf" target="_blank">recently published</a> in <em>The Astrophysical Journal Letters</em>.&nbsp;Noble is a member of the research group of&nbsp;Kavli Institute astronomer and assistant professor of physics Michael McDonald, who is the second author on the&nbsp;paper. &nbsp;</p>
<p><a href="http://www.physics.ucr.edu/people/faculty/wilson.html" target="_blank">Gillian Wilson</a>, a professor of&nbsp;<a href="http://www.physics.ucr.edu/">physics and astronomy</a>&nbsp;at the University of California at Riverside and the leader of the SpARCS collaboration, says that while the&nbsp;current study "does not answer the question of which physical process is primarily responsible for causing the higher amounts of molecular gas, it provides the most accurate measurement yet of how much molecular gas exists in galaxies in clusters in the early universe.”&nbsp;</p>
The Tadpole Galaxy, a disrupted spiral galaxy, shows streams of gas stripped by gravitational interaction with another galaxy. Molecular gas is the required ingredient to form stars in early universe galaxies. Photo: Hubble Legacy Archive, European Space Agency, NASA, Bill SnyderAstronomy, Astrophysics, Collaboration, Kavli Institute, School of Science, Space, astronomy and planetary science, ResearchOnline program wins engineering education awardhttps://news.mit.edu/2017/mit-boeing-online-architecture-and-systems-engineering-program-receives-award-excellence-engineering-education-0630
More than 1,600 professionals have completed the Architecture and Systems Engineering course series developed by MIT in collaboration with Boeing and edX.Fri, 30 Jun 2017 13:25:01 -0400Office of Digital Learninghttps://news.mit.edu/2017/mit-boeing-online-architecture-and-systems-engineering-program-receives-award-excellence-engineering-education-0630<p>In collaboration with Boeing and edX, MIT has been&nbsp;honored with the 2017 Excellence in Engineering Education Collaboration Award by the American Society for Engineering Education (ASEE).</p>
<p>The team was chosen for its design and development of a new four-course online professional certification program called&nbsp;<a href="https://sysengonline.mit.edu/?utm_source=mitnews&amp;utm_campaign=dls-sysengx-run3&amp;utm_medium=referral&amp;utm_content=dls-sysengx-story">Architecture and Systems Engineering: Models and Methods to Manage Complex Systems</a>. The curriculum explores state-of-the-art practices in systems engineering&nbsp;and also demonstrates the value of models in enhancing system engineering functions and augmenting tasks with quantitative analysis.</p>
<p>The program launched last&nbsp;September and ran through March. Nine faculty members from MIT and more than 25 industry experts from Boeing, NASA, IBM, Apple, General Electric, General Motors, and other companies developed content for the courses. More than 1,600 professionals passed the four&nbsp;courses and earned a certificate in the first run of the program. Currently in its second run, the program is now&nbsp;<a href="https://sysengonline.mit.edu/?utm_source=mitnews&amp;utm_campaign=dls-sysengx-run3&amp;utm_medium=referral&amp;utm_content=dls-sysengx-story" target="_blank">accepting enrollments</a>&nbsp;for September.</p>
<p>“For companies engaged in the development of complex systems, the ability to track the architecture over time is a core competence,” says Bruce Cameron, director of the System Architecture Lab at MIT and faculty director of the program. “As the complexity of the products we produce today increases, engineers face critical challenges managing these systems in the rapidly evolving environment around them. This program prepares the workforce to better face these challenges.”</p>
<p>The program is delivered on the edX platform, with integrated peer-to-peer assessments, group projects, discussion forums, polls, and surveys. In course feedback on the program, more than 93 percent of survey respondents rated the instructors&nbsp;and&nbsp;materials as “good,” “very good,” or “excellent”.</p>
<p>“For my client base, time is the most valuable asset they have. More than money,” explains Michael Fletcher, president of Fletcher Martin Corporation, who earned his professional certificate in March. “When you have a project that's squished into 20 weeks from planning to final completion and there’s a change, a ripple effect happens. Finding ways to minimize that ripple effect and conserve time and money is invaluable. [This program] really built a structured way of thinking that I didn't have before, and brought up a whole new set of ideas. I can't wait to get some models built.”</p>
<p>The development of the program can be traced&nbsp;back to the Space Act Agreement of 2016, when Boeing and NASA joined forces to strengthen engineering and technical leadership capabilities in the&nbsp;United States&nbsp;through innovative educational initiatives. They enlisted MIT and edX to help them create the program. MIT then built a consortium to inform the design of the program, which includes&nbsp;General Electric, Raytheon, Ford, MITRE, and General Motors.</p>
<p>“This partnership with MIT, edX, and NASA blends the expertise of industry, government, and a world-class academic institution to provide a unique educational experience in systems engineering, an area of critical importance to Boeing,” said Greg Hyslop, Boeing's chief technology officer and senior vice president of Engineering, Test and Technology. “That’s a win-win-win for all of us involved, and for the future of aerospace innovation as it’s now applied to learning.”</p>
<p>To earn a certificate, students must complete four courses: Architecture of Complex Systems;&nbsp;Models in Engineering;&nbsp;Model-Based Systems Engineering: Documentation and Analysis;&nbsp;and Quantitative Methods in Systems Engineering. Upon completion, participants are expected&nbsp;to understand and analyze complex systems, perform model management, frame systems architecture as a series of decisions, articulate the benefits and challenges of model-based systems engineering, and demonstrate a comprehensive knowledge of the key aspects of systems engineering.</p>
<p>“The market already offers many educational opportunities around specific tools and new modeling languages. We wanted to offer an overview on why and when to use the tools, in a format that fits into 4-5 hours per week to be compatible with a full-time job,” Cameron says. “The great challenge of system engineering is to foster communication across disciplines —&nbsp;this program builds in a variety of domain examples. ”</p>
<p>Lectures include architectural representations ranging from electrical layout to&nbsp;CAD drawings&nbsp;to functional block diagrams. “That spread is very intentional from our perspective,” Cameron says.</p>
<p>Anant Agarwal, the CEO of edX&nbsp;and an MIT professor, says the&nbsp;success&nbsp;of&nbsp;the&nbsp;program “is a&nbsp;result of edX, MIT, and Boeing’s, combined commitment to providing&nbsp;flexible, highly-engaging digital offerings for professional education at scale and at a fraction of the traditional cost.”</p>
<p>“Together, we are reinventing the way that practicing engineers of hugely complex systems gain access to the new thinking, processes, and tools that help them become more efficient,” Agarwal says.</p>
<p>ASEE, the award sponsor, created the Excellence in Engineering Education Collaboration Awards to demonstrate best practices in collaboration that enhance engineering education. The award competition is open&nbsp;to all ASEE Corporate Member Council organizations&nbsp;for their development of collegiate-level education programs and pre-college programs that generate curiosity and engage students in STEM education.</p>
<p>The award was presented at the 2017 ASEE Annual Conference in Columbus, Ohio, during the Industry Day Plenary Session on&nbsp;June 27.</p>
American Society for Engineering Education President Bevlee Watford (left) presents the 2017 ASEE Excellence in Engineering Collaboration Award to Boeing executives Christi Gau Pagnanelli (center) and Mark Cousino.Photo courtesy of ASEE.Office of Digital Learning, Awards, honors and fellowships, Classes and programs, Collaboration, Computer modeling, EdX, online learning, NASA, IndustryRainer Weiss wins Princess of Asturias Award for Technical and Scientific Researchhttps://news.mit.edu/2017/rainer-weiss-wins-princess-of-asturias-award-for-technical-and-scientific-research-0627
Prestigious Spanish award shared with Caltech&#039;s Kip Thorne and Barry Barish and the LIGO Scientific Collaboration for work in detecting gravitational waves. Thu, 29 Jun 2017 11:00:01 -0400MIT Kavli Institute for Astrophysics and Space Researchhttps://news.mit.edu/2017/rainer-weiss-wins-princess-of-asturias-award-for-technical-and-scientific-research-0627<p>The 2017 Princess of Asturias Award for Technical and Scientific Research was awarded on June 14 to MIT Professor Emeritus Rainer Weiss and to Caltech physicists Kip S. Thorne and Barry C. Barish and the LIGO Scientific Collaboration.</p>
<p>Weiss was one of the inventors of the laser interferometer gravitational wave detector in the 1970s and co-founded with Thorne and the late Ronald Drever the National Science Foundation Laser Interferometer Gravitational-wave Observatory (LIGO) project in the 1980s to detect gravitational waves. Astronomers had strong indirect evidence for gravitational waves from the measurements of a binary pulsar system between 1970 to 1990. But on Sept. 14, 2015, LIGO made the first direct detection of gravitational waves from the collision of two black holes.</p>
<p>The measurement came from Advanced LIGO, an upgraded version of LIGO’s two large interferometers at Hanford, Washington, and Livingston, Louisiana. Two other detections have been confirmed since then, with the most recent occurring on Jan. 4 of this year. The detections have confirmed Einstein's field equations in the limit of strong gravity and have opened a new field: gravitational wave astronomy.</p>
<p>In addition to receiving the 2017 Princess of Asturias Award for Technical and Scientific Research, Weiss’ contributions to the field for more than 40 years have resulted in numerous awards, including the 2016 Kavli Prize in Astrophysics, a Special Breakthrough Prize in Fundamental Physics, the 2016 Gruber Prize in Cosmology, and the Shaw Prize in Astronomy.</p>
<p>The Princess of Asturias Foundation presents the Asturias Awards for research and discoveries that "contribute to extolling and promoting those scientific, cultural, and humanistic values that form part of the universal heritage of humanity." Weiss and his team were chosen from a field of 39 candidates from 17 different countries. The awards will be presented this autumn in Oviedo, Spain, at a ceremony presided over by Queen Letizia Ortiz Rocasolano and King Felipe VI, the monarchs of Spain. Each awardee will receive a cash prize of 50,000 euros, a diploma, and an insignia. The winners will also receive a sculpture of Joan Miró, one of Spain’s most celebrated artists.</p>
Rainer WeissPhoto: Bryce VickmarkAwards, honors and fellowships, Faculty, LIGO, Kavli Institute, Astrophysics, Black holes, National Science Foundation (NSF), School of Science, SpainMIT space hotel wins NASA graduate design competitionhttps://news.mit.edu/2017/mit-space-hotel-wins-nasa-graduate-design-competition-0628
Module would serve as a commercially owned space station, featuring a luxury hotel as the primary anchor tenant and NASA as a temporary co-anchor tenant.Wed, 28 Jun 2017 11:40:01 -0400System Design and Management Programhttps://news.mit.edu/2017/mit-space-hotel-wins-nasa-graduate-design-competition-0628<p>An interdisciplinary team of MIT graduate students representing five departments across the Institute was recently honored at NASA's Revolutionary Aerospace Systems Concepts-Academic Linkage Design Competition Forum. The challenge involved designing a commercially enabled habitable module for use in low Earth orbit that would be extensible for future use as a Mars transit vehicle. The team’s design won first place in the competition’s graduate division.</p>
<p>The MIT project — the Managed, Reconfigurable, In-space Nodal Assembly (MARINA) — was designed as a commercially owned and operated space station, featuring a luxury hotel as the primary anchor tenant and NASA as a temporary co-anchor tenant for 10 years. NASA’s estimated recurring costs, $360 million per year, represent an order of magnitude reduction from the current costs of maintaining and operating the International Space Station. Potential savings are approximately 16 percent of NASA’s overall budget — or around $3 billion per year.</p>
<p>MARINA team lead Matthew Moraguez, a graduate student in MIT’s Department of Aeronautics and Astronautics and a member of Professor Olivier L. de Weck’s&nbsp;<a href="http://strategic.mit.edu/" target="_blank">Strategic Engineering Research Group</a>&nbsp;(SERG), explained that MARINA’s key engineering innovations include extensions to the International Docking System Standard (IDSS) interface; modular architecture of the backbone of MARINA’s node modules; and a distribution of subsystem functions throughout the node modules.</p>
<p>“Modularized service racks connect any point on MARINA to any other point via the extended IDSS interface. This enables companies of all sizes to provide products and services in space to other companies, based on terms determined by the open market,” Moraguez said. “Together these decisions provide scalability, reliability, and efficient technology development benefits to MARINA and NASA.”</p>
<p>MARINA’s design also enables modules to be reused to create an interplanetary Mars transit vehicle that can enter Mars’ orbit, refuel from locally produced methane fuel, and return to Earth.</p>
<p>MARINA and SERG team member George Lordos MBA '00 is currently a graduate fellow in the MIT <a href="http://sdm.mit.edu/" target="_blank">System Design and Management&nbsp;(SDM) Program</a>, which is offered jointly by the MIT School of Engineering and the MIT Sloan School of Management. Lordos pointed out that MARINA’s engineering design innovations are critical enablers of its commercial viability, which rests on MARINA’s ability to give rise to a value-adding, competitive marketplace in low Earth orbit.</p>
<p>“Just like a yacht marina, MARINA can provide all essential services, including safe harbor, reliable power, clean water and air, and efficient logistics and maintenance,” said Lordos, who will enter the MIT aeronautics and astronautics doctoral program this fall. “This will facilitate design simplicity and savings in construction and operating costs of customer-owned modules. It will also incent customers to lease space inside and outside MARINA’s node modules and make MARINA a self-funded entity that is attractive to investors.”</p>
<p>Valentina Sumini, a postdoc at MIT, contributed to the architectural concept being used for MARINA and its space hotel, along with MARINA faculty advisor Assistant Professor Caitlin Mueller of MIT’s School of Architecture and Planning and Department of Civil and Environmental Engineering.</p>
<p>“MARINA’s flagship anchor tenant, a luxury Earth-facing eight-room space hotel complete with bar, restaurant, and gym, will make orbital space holidays a reality,” said Sumini.</p>
<p>Other revenue-generating features include rental of serviced berths on external International Docking Adapter ports for customer-owned modules and rental of interior modularized rack space to smaller companies that provide contracted services to station occupants. These secondary activities may involve satellite repair, in-space fabrication, food production, and funded research.</p>
<p>Additional members of the MARINA team include: MIT Department of Aeronautics and Astronautics graduate students and SERG members Alejandro Trujillo, Samuel Wald, and Johannes Norheim; MIT Department of Civil and Environmental Engineering undergraduate Zoe Lallas; MIT School of Architecture and Planning graduate students Alpha Arsano and Anran Li; and MIT Integrated Design and Management Program graduate students Meghan Maupin and John Stillman.</p>
The Managed, Reconfigurable, In-space Nodal Assembly (MARINA), developed by MIT graduate students, recently took first place at NASA's Revolutionary Aerospace Systems Concepts-Academic Linkage Design Competition Forum. MARINA is designed as a habitable commercially owned module for use in low Earth orbit that would be extensible for future use as a Mars transit vehicle.Students, Graduate, postdoctoral, Awards, honors and fellowships, NASA, Space exploration, Space, astronomy and planetary science, Design, System Design and Management, School of Engineering, Aeronautical and astronautical engineering, Civil and environmental engineering, Sloan School of Management, School of Architecture and PlanningProbing the magnetic universehttps://news.mit.edu/2017/mit-plasma-science-and-fusion-center-associate-professor-nuno-loureiro-probing-origins-of-the-magnetic-universe-0623
Nuclear Science and Engineering Associate Professor Nuno Loureiro ponders the origins of magnetic fields.Fri, 23 Jun 2017 12:45:01 -0400Paul Rivenberg | Plasma Science and Fusion Centerhttps://news.mit.edu/2017/mit-plasma-science-and-fusion-center-associate-professor-nuno-loureiro-probing-origins-of-the-magnetic-universe-0623<p>Nuclear Science and Engineering Associate Professor Nuno Loureiro has spent his first year and a half at MIT’s Plasma Science and Fusion Center (PSFC) exploring the magnetic processes&nbsp;crucial to understanding how to sustain fusion in a tokamak&nbsp;like the Center’s&nbsp;<a class="external" href="http://news.mit.edu/2016/alcator-c-mod-tokamak-nuclear-fusion-world-record-1014" style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; font-style: inherit; font-variant: inherit; font-weight: inherit; font-stretch: inherit; font-size: inherit; line-height: inherit; font-family: inherit; vertical-align: baseline; color: rgb(0, 114, 188); text-decoration-line: none; outline: none;" target="_blank">Alcator C-Mod</a>&nbsp;project. Now, with the help of a National Science Foundation Early Career Development award, he is also looking beyond the fusion vacuum chamber to the edges of the universe, seeking an answer to a fundamental astrophysical question: How did the universe magnetize itself?</p>
<p>Loureiro marvels at how pervasive magnetic fields are, evident not only in planets and the interplanetary medium, but beyond the heliosphere to the interstellar, galactic, intergalactic, and intercluster media. But how were these fields generated?&nbsp;And how did they come to have the structure and magnitude they have today?</p>
<p>“We now strongly believe that these magnetic fields critically affect structure formation in the universe —&nbsp;they are critical to shaping the world as we see it. In a sense, the existence of magnetic fields may be the reason you and I are having this conversation,” Loureiro says.</p>
<p>Scientists now believe that magnetic fields were not created with the Big Bang, but must have been generated later. Because the universe is largely plasma, researchers are looking&nbsp;to the plasma processes that could have created these fields. Loureiro knows that a magnetic field can grow in strength and structure by interacting with plasma.</p>
<p>“If you give me a tiny amplitude magnetic field — weaker than a fridge magnet, for example —&nbsp;then you can use a process called plasma dynamo, which is nothing more than stirring that magnetic field with a turbulent flow,” he says. “Because plasmas are electrically conducting media, they interact with the magnetic field, so if you stir the plasma you stir the magnetic field as well. In the process, the plasma dynamo will exponentially amplify the magnetic field.”</p>
<p>The question for Loureiro is:&nbsp;Can you amplify a small magnetic seed field, via a plasma dynamo, to levels we observe today in less time than the current age of the universe? And of course:&nbsp;How does a magnetic seed field form in the first place?</p>
<p>The project, which relies on theory and simulations, requires a deep understanding of magnetic reconnection and turbulence in plasmas, topics that have been Loureiro’s focus since he was a graduate student at Imperial College&nbsp;London. He is delighted to be putting his expertise to use. “I’m not going to be using magnetic reconnection as a goal, which I’ve been doing so far, but as a tool,” he notes.</p>
<p>Loureiro is originally&nbsp;from Portugal, where he was head of the Theory and Modeling Group of the Institute for Plasmas and Nuclear Fusion at the Instituto Superior Técnico (IST) in Lisbon.&nbsp;He&nbsp;is now Assistant Head of the Theory and Modeling division at the PSFC, and an associate professor with tenure. He joined MIT in January 2016, but only after having determined with his family that they were ready to embrace the uncertainty and unpredictability of a new home. He says&nbsp;the move has been stimulating and rewarding for everyone.</p>
<p>“Professionally I’m completely overwhelmed with what MIT is,” he says. &nbsp;“You read about it and you talk to people about it, but before you’ve experienced it, I don’t think you quite understand the type of place it is. It’s fascinating to be here, surrounded by so many amazing people. It’s&nbsp;inspirational.”</p>
“We now strongly believe that these magnetic fields critically affect structure formation in the universe — they are critical to shaping the world as we see it," says Associate Professor Nuno Loureiro.Photo: Susan YoungNuclear science and engineering, Plasma Science and Fusion Center, Astrophysics, Fusion, Nuclear power and reactors, Planetary science, space, Space, astronomy and planetary science, School of EngineeringSpace junk: The cluttered frontierhttps://news.mit.edu/2017/space-junk-shards-teflon-0619
New laser technique identifies the makeup of space debris, from painted shards to Teflon.Mon, 19 Jun 2017 09:00:00 -0400Jennifer Chu | MIT News Officehttps://news.mit.edu/2017/space-junk-shards-teflon-0619<p>Hundreds of millions of pieces of space junk orbit the Earth daily, from chips of old rocket paint, to shards of solar panels, and entire dead satellites. This cloud of high-tech detritus whirls around the planet at about 17,500 miles per hour. At these speeds, even trash as small as a pebble can torpedo a passing spacecraft.</p>
<p>NASA and the U.S. Department of Defense are using ground-based telescopes and laser radars (ladars) to track more than 17,000 orbital debris objects to help prevent collisions with operating missions. Such ladars shine high-powered lasers at target objects, measuring the time it takes for the laser pulse to return to Earth, to pinpoint debris in the sky.</p>
<p>Now aerospace engineers from MIT have developed a laser sensing technique that can decipher not only where but what kind of space junk may be passing overhead. For example, the technique, called laser polarimetry, may be used to discern whether a piece of debris is bare metal or covered with paint. The difference, the engineers say, could help determine an object’s mass, momentum, and potential for destruction.</p>
<p>“In space, things just tend to break up over time, and there have been two major collisions over the last 10 years that have caused pretty significant spikes in debris,” says Michael Pasqual, a former graduate student in MIT’s Department of Aeronautics and Astronautics. “If you can figure out what a piece of debris is made of, you can know how heavy it is and how quickly it could deorbit over time or hit something else.”</p>
<p>Kerri Cahoy, the Rockwell International Career Development Associate Professor of aeronautics and astronautics,&nbsp;and an associate professor in the Department of Earth, Atmospheric, and Planetary Sciences at MIT, says the technique can easily be implemented on existing groundbased systems that currently monitor orbital debris.</p>
<p>“[Government agencies] want to know where these chunks of debris are, so they can call the International Space Station and say, ‘Big chunk of debris coming your way, fire your thrusters and move yourself up so you’re clear,’” Cahoy says. “Mike came up with a way where, with a few modifications to the optics, they could use the same tools to get more information about what these materials are made of.”</p>
<p>Pasqual and Cahoy have published their results in the journal <em>IEEE Transactions on Aerospace and Electronic Systems.</em></p>
<p><strong>Seeing a signature</strong></p>
<p>The team’s technique uses a laser to measure a material’s effect on the polarization state of light, which refers to the orientation of light’s oscillating electric field that reflects off the material. For instance, when the sun’s rays reflect off a rubber ball, the incoming light’s electric field may oscillate vertically. But certain properties of the ball’s surface, such as its roughness, may cause it to reflect with a horizontal oscillation instead, or in a completely different orientation. The same material can have multiple polarization effects, depending on the angle at which light hits it.</p>
<p>Pasqual reasoned that a material such as paint could have a different polarization “signature,” reflecting laser light in patterns that are distinct from the patterns of, say, bare aluminum. Polarization signatures therefore could be a reliable way for scientists to identify the composition of orbital debris in space.&nbsp;</p>
<p>To test this theory, he set up a benchtop polarimeter — an apparatus that measures, at many different angles, the polarization of laser light as it reflects off a material. The team used a high-powered laser beam with a wavelength of 1,064 nanometers, similar to the lasers used in existing ground-based ladars to track orbital debris. The laser was horizontally polarized, meaning that its light oscillated along a horizontal plane. Pasqual then used polarization filtering optics and silicon detectors to measure the polarization states of the reflected light.</p>
<p><strong>Sifting through space trash</strong></p>
<p>In choosing materials to analyze, Pasqual picked six that are commonly used in satellites: white and black paint, aluminum, titanium, and Kapton and Teflon — two filmlike materials used to shield satellites.</p>
<p>“We thought they were very representative of what you might find in space debris,” Pasqual says.</p>
<p>He placed each sample in the experimental apparatus, which was motorized so measurements could be made at different angles and geometries, and measured its polarization effects. In addition to reflecting light with same polarization as the incident light, materials can also display other, stranger polarization behaviors, such as rotating the light’s oscillation slightly — a phenomenon called retardance. Pasqual identified 16 main polarization states, then took note of which efffects a given material exhibited as it reflected laser light.</p>
<p>“Teflon had a very unique property where when you shine laser light with a vertical oscillation, it spits back some in-between angle of light,” Pasqual says. “And some of the paints had depolarization, where the material will spit out equal combinations of vertical and horizontal states.”</p>
<p>Each material had a suffiiciently unique polarization signature to distinguish it from the other five samples. Pasqual believes other aerospace materials, such as various shielding films, or composite materials for antennas, solar cells, and circuit boards, may also exhibit unique polarization effects. His hope is that scientists can use laser polarimetry to establish a library of materials with unique polarization signatures. By adding certain filters to lasers on existing groundbased ladars, scientists can measure the polarization states of passing debris and match them to a library of signatures to determine the object’s composition.</p>
<p>“There are already a lot of facilities on the ground for tracking debris as it is,” Pasqual says. “The point of this technique is, while you’re doing that, you might as well put some filters on your detectors that detect polarization changes, and it’s those polarization features that can help you infer what the material is made of. And you can get more information, basically for free.”</p>
<p>This research was supported, in part, by the MIT Lincoln Scholars Program.</p>
Aerospace engineers from MIT have developed a laser sensing technique that can decipher not only where but what kind of space junk may be passing overhead.
Materials Science and Engineering, NASA, Research, Satellites, Space, astronomy and planetary science, Aeronautical and astronautical engineering, School of Engineering, EAPS, Earth and Planetary ScienceNASA selects three from MIT for astronaut traininghttps://news.mit.edu/2017/nasa-selects-three-from-mit-for-astronaut-training-0613
Chari, Hoburg, and Moghbeli, all with ties to the Department of Aeronautics and Astronautics, represent a quarter of NASA&#039;s astronaut candidate Class of 2017.Tue, 13 Jun 2017 13:25:01 -0400Bill Litant | Department of Aeronautics and Astronauticshttps://news.mit.edu/2017/nasa-selects-three-from-mit-for-astronaut-training-0613<p>When asked, “What do I have to do to become an astronaut?” MIT professor of aeronautics and astronautics and <span class="s1">Dibner Professor of the History of Engineering and Manufacturing</span> David Mindell says he semi-seriously responds, “Go get a degree from MIT.”</p>
<p>It certainly seems that advice has merit: Last week, <a href="https://www.nasa.gov/press-release/nasa-s-newest-astronaut-recruits-to-conduct-research-off-the-earth-for-the-earth-and" target="_blank">NASA announced</a> it had added three MIT alumni — including one current faculty member in the Department of Aeronautics and Astronautics (AeroAstro) — to its 12-member 2017 astronaut candidate class, bringing up the total number of <a href="https://twitter.com/MIT/status/719949516825313280" target="_blank">MIT astronaut alumni</a> to 41.</p>
<p>The new MIT astronaut candidates, all AeroAstro alumni selected from an applicant pool of more than 18,000, are:</p>
<p><a href="https://www.nasa.gov/astronauts/biographies/raja-chari/biography" target="_blank">Raja Chari</a> SM ’01, a U.S. Air Force lieutenant colonel who commands the 461st Flight Test Squadron and directs the F-35 Integrated Task Force;</p>
<p><a href="https://www.nasa.gov/astronauts/biographies/warren-hoburg/biography" target="_blank">Warren “Woody” Hoburg</a> ’08, an MIT assistant professor of AeroAstro who teaches undergraduate courses on dynamics and flight vehicle engineering; and</p>
<p><a href="https://www.nasa.gov/astronauts/biographies/jasmin-moghbeli/biography" target="_blank">Jasmin Moghbeli</a> ’05, a U.S. Marine Corps major serving as the quality assurance and avionics officer for the Marine Operational Test and Evaluation Squadron.</p>
<p>This summer, the new astronaut candidates will begin two years of training. Subsequently, they will be available for a variety of missions, which may involve research on the International Space Station, launching aboard spacecraft built by commercial companies, or departing for deep-space missions on NASA’s new Orion spacecraft.</p>
<p>With this latest class, MIT AeroAstro has produced 17 alumni astronauts. Four of the men who walked on the moon were Course 16 alumni: Buzz Aldrin ScD ’63, Ed Mitchell ScD ’64, Charlie Duke SM ’64, and David Scott SM/EAA ’62. Meanwhile, Jack Fischer SM ’98 is <a href="https://twitter.com/MIT/status/868166122889248768" target="_blank">currently a crewmember</a> on the International Space Station.</p>
<p>“While educating future astronauts isn’t exactly an explicit part of our curriculum, it’s clear that NASA very much values the skills learned at MIT when it’s parsing the thousands of applications for candidates,” says Jaime Peraire, head of AeroAstro and the H.N. Slater Professor of Aeronautics and Astronautics. “And, of course, we’re extremely proud of these young women and men.”</p>
Three from MIT will train as NASA astronauts beginning in August: Raja Chari SM '01 (left), Jasmin Moghbeli '05 (center), and Assistant Professor Warren “Woody” Hoburg '08.Photos: Robert Markowitz/NASANASA, Faculty, Alumni/ae, Aeronautics and Astronautics, Space exploration, Space, astronomy and planetary science, School of EngineeringHacking apparel becomes lucrative business for alumnihttps://news.mit.edu/2017/hacking-apparel-becomes-lucrative-business-alumni-0607
Clothing tinkerers innovate fashion with science-based performance dresswear and 3-D knitting.Wed, 07 Jun 2017 16:00:00 -0400Rob Matheson | MIT News Officehttps://news.mit.edu/2017/hacking-apparel-becomes-lucrative-business-alumni-0607<p>Gihan Amarasiriwardena ’11 has always been a hacker, but not the traditional kind: He hacks clothing and outdoor gear. Since adolescence, he’s cobbled together custom waterproof jackets, heat-trapping sleeping bags, and performance dress shirts.</p>
<p>In 2012, that hobby led Amarasiriwardena to co-found, with other MIT clothing tinkerers, Ministry of Supply, a Boston-based innovator of high-tech fashion. The company has developed a rapidly growing science-based clothing line and the industry’s first 3-D robotic knitting machine.</p>
<p>“The mission and vision of this company is inventing apparel. It’s very MIT in that regard. Instead of hacking code, we’re hacking fibers,” says Amarasiriwardena, who co-founded Ministry of Supply with MIT Sloan School of Management students Aman Advani and Kit Hickey MBA ’13, and mechanical engineering alumnus Kevin Rustagi ’11.</p>
<p>Having last year expanded nationwide, both online and to nine retail locations, Ministry sells about 100,000 products annually, ranging from aerospace-tech dress shirts to socks that use coffee grounds to mitigate odor. In April, the startup launched the fashion industry’s first machine designed to 3-D-knit personalized blazers on demand.</p>
<p>Customers can plug blazer customizations — such as size, and yarn, button, and cuff color —&nbsp;into a computer at the machine, a 10-foot-long printer set up near the checkout counter of Ministry’s Newbury Street headquarters. An image appears on an interactive display, and modifications can be made on the fly. Inside the machine, four beds with 4,000 needles each pull yarn to knit the garment. In about 90 minutes, the machine spits out a blazer that stays at the store a couple days for finishing touches such as steaming and shrinking. According to the startup, the machine eliminates about 30 percent of the fabric waste of traditional cut-and-sew methods.</p>
<p>Ministry of Supply collaborated with the manufacturer, Shima Seiki, to “hack” the machine to make blazers, by using thermoset yarn that shrinks to size, among other innovations. The first 3-D-knitted garments sold out in a day, and the machine has since become popular with customers. But, Amarasiriwardena says, the machine is important for another reason: “It’s a testament to our technology roots.”</p>
<p><strong>Creating the first “Franken-shirt”</strong></p>
<p>As a boy scout and frequent camper in high school, Amarasiriwardena sought to make better outdoor clothing and gear. To make a waterproof jacket, for instance, he laminated fleece onto flimsy trash bags. Soon, he graduated to sticking ripstop — material used for rain jackets — onto a more breathable housewrap material he grabbed from construction sites. He’d also run Mylar, a material used for thermal blankets, through his parents’ paper shredder and stuff the strips into the lining of his sleeping bag so it would reflect any heat back to his body.</p>
<p>“It was these small hacks that made me think I would someday start an outdoor gear company or performance material company,” Amarasiriwardena says.</p>
<p>But when he started studying chemistry and biological engineering at MIT, and was biking daily, he experienced a major problem: There were no performance dress clothes. “The performance gear I wore wicked away moisture, and kept you cool and dry, but didn’t cut it when it came to looking sharp. I realized there’s a big opportunity to take technology to clothing that we wear for 12 hours a day, when we’re not at the gym or on the mountain,” he says.</p>
<p>Supported by MIT International Science and Technology Initiatives (MISTI) and Sports Technology Education at MIT (STE@M), Amarasiriwardena spent two summers at the Sports Technology Institute at Loughborough University in England, where he and other researchers conducted clothing stress-strain analyses. Sticking sensors on test subjects’ chest, back, and dress shirt, they tracked how the skin and material stretch. They noted lateral stretching at the top of a person’s back where, on traditional dress shirts, there’s a straight, inflexible seam. “You can imagine someone hunching over bike, while biking to work, and the material not stretching,” Amarasiriwardena says.</p>
<p>Back at his Phi Kappa Theta fraternity chapter room, Amarasiriwardena cut up running shirts and sewed them into wrinkle-free dress shirts. On the back, he added a stretchy, curved polyester panel that allowed for stretching. To the underarms, he sewed patches of odor-control material made of <em>silver-based</em> antimicrobial fabric. “It looked like a ‘Franken-shirt,’ but it did the job,” Amarasiriwardena says, laughing.</p>
<p>With Rustagi, a friend and mechanical engineering student, Amarasiriwardena began selling the shirts around campus, while taking 15.3901 (New Enterprises).</p>
<p><strong>Launching Apollo</strong></p>
<p>In the fall of 2011, the duo set up shop in the Martin Trust Center for MIT Entrepreneurship to make performance dress clothes. In a remarkable coincidence, they met a separate team that included Hickey and Advani, a trained industrial engineer with a similar hobby: He had cut off the bottoms of his dress socks and sewn on material from moisture-wicking running socks. Hickey and Advani’s team was making performance underwear, socks, and undershirts for professionals. “That’s the beauty of the Entrepreneurship Center, which is kind of this intersection of engineering, design, and marketing and business coming together,” Amarasiriwardena says.</p>
<p>At the time, early team member Eddie Obropta ’13, SM ’15, was working in MIT’s Man Vehicle Laboratory on spacesuits for astronauts traveling to Mars. The materials in the suits basically melt and freeze based on skin temperature by absorbing any excess heat from the body, so they could withstand extreme temperature swings on the Red Planet.</p>
<p>After coming together to form Ministry of Supply — named after the defunct department of the U.K. government responsible for designing and supplying equipment to the British armed forces — the team used similar temperature-regulating materials to invent the Apollo dress shirt for professionals.</p>
<p>“Riding the T in the summer in Boston, it could be 95 degrees. As your body temperature starts to elevate, the material will melt around your skin temperature, storing that heat in the shirt. When you get into an air-conditioned office, it freezes and releases that heat back to you,” Amarasiriwardena explains.</p>
<p>After selling about 700 of the shirts around Boston, gathering feedback from wearers, and developing a refined prototype, the startup launched a Kickstarter campaign in 2012, with a goal of $30,000. They raised $430,000, making this the most-funded fashion project on the site.</p>
<p><strong>Engineering fashion</strong></p>
<p>Since then, Ministry has opened nine stores across the country and developed a growing clothing line of pants, shirts, socks, and sweaters for men and women, made with the temperature-control technology, form-fitting material based on NASA spacesuits, and stretchable materials derived from Amarasiriwardena’s early experiments. A notable innovation was a line of socks with spent coffee grounds —&nbsp;residue obtained during the brewing process — mixed into the yarn for odor control.</p>
<p>“With spent coffee grounds, you dilute the coffee flavor and aroma, and you’re left with organic sponge that will trap any aromatic compounds, or odor molecules, and absorb them into fabric,” Amarasiriwardena says. In 2013, the startup launched a Kickstarter just for the socks, seeking $30,000 and raising more than $200,000.</p>
<p>Key to the startup’s success, Amarasiriwardena says, has been its scientific iterating process. For each new garment, the startup researches, designs a prototype for customers to test, and gathers client feedback on moisture management, flexibility, new dyes, and knit structures, among other features. “It’s a process fundamental to engineering, but one that’s absent in traditional apparel design, where you don’t see a design until it hits the runway. That’s often times why fashion has focused on style changes but not making apparel better,” Amarasiriwardena says.</p>
<p>As for the new 3-D knitting machine, Amarasiriwardena says it isn’t just a gimmick — it’s the future of fashion. Right now, the machine can only make blazers, but the startup plans to tweak it to produce other garments. Taking up such a large part of the store, Amarasiriwardena adds, the machine is also a great educational tool, where customers can see how their clothing is made and learn about the 3-D-knitting process. “Technology shouldn’t be something that you are afraid of and have to hide away,” he says. “It can actually be a key part of the retail experience.”</p>
(Left to right): Kit Hickey, chief retail officer; Aman Advani, CEO; and Gihan Amarasiriwardena, chief design officer.
Courtesy of Ministry of SupplySchool of Engineering, Sloan School of Management, School of Science, Mechanical engineering, Biological engineering, Chemistry, Startups, Innovation and Entrepreneurship (I&E), Alumni/ae, Business and management, Aeronautical and astronautical engineering, Materials Science and Engineering, NASA, Manufacturing, Industry, 3-D printingLIGO detects merging black holes for third timehttps://news.mit.edu/2017/ligo-detects-merging-black-holes-third-time-0601
Nearly 3 billion light years from Earth, the black holes are the farthest ever detected. Thu, 01 Jun 2017 10:59:59 -0400Jennifer Chu | MIT News Officehttps://news.mit.edu/2017/ligo-detects-merging-black-holes-third-time-0601<p>The collision of a pair of colossal, stellar-mass black holes has made itself heard, nearly 3 billion light years away, through a cosmic microphone on Earth.</p>
<p>On Jan. 4, the Laser Interferometry Gravitational-wave Observatory (LIGO) picked up a barely perceptible signal that scientists quickly determined to be a gravitational wave — a ripple of energy passing through the curvature of spacetime. The event, published today in <em>Physical Review Letters</em>, marks the third direct detection of a gravitational wave.</p>
<p>Catalogued as GW170104, the signal, when translated into the audio band, resembles an upward-sweeping chirp, characteristic of a “binary coalescence,” or a merging of two massive astrophysical objects in the distant universe. The team has concluded that the gravitational wave was produced by the collision of two heavy, stellar–mass black holes, one estimated to be about 31 times, and the other 19 times, as massive as the sun.</p>
<p>The signal captured by LIGO lasts less than two-tenths of a second, and in that fraction of a moment, scientists calculate that the black holes whirled around each other about six times before merging into one giant, 49-solar-mass black hole. This cosmic collision gave off an enormous amount of energy in the form of gravitational waves, equivalent to two times the mass of the sun.</p>
<p>The merger took place about 3 billion light years from Earth, measuring about twice as far as the black hole collision that produced GW150914, LIGO’s first-ever gravitational wave detection.</p>
<p>“This is indeed the farthest out stellar-mass black hole system anyone has seen,” says Erik Katsavounidis, senior research scientist in MIT’s Kavli Institute for Astrophysics and Space Research and a member of the LIGO team.</p>
<p><img alt="" src="/sites/mit.edu.newsoffice/files/black-hole-ligo3-small.gif" /></p>
<p><span style="font-size:10px;"><strong>A mathematical simulation of the warped space-time near two merging black holes, consistent with LIGO's observation of the event dubbed GW170104. The colored bands are gravitational-wave peaks and troughs, with the colors getting brighter as the wave amplitude increases. (Image: SXS Collaboration)</strong></span></p>
<p><strong>Out of alignment</strong></p>
<p>The new gravitational wave signal is similar to LIGO’s first two detections, both in its source — a binary black hole merger — and the overall mass of that source.</p>
<p>However, the scientists discovered an interesting feature in the newest signal: The spin of at least one of the black holes may have been “antialigned” with the orbital angular momentum — the direction in which the black holes were orbiting each other. This phenomenon would be similar to teacups spinning counterclockwise on a clockwise-rotating carnival platform.</p>
<p>Katsavounidis stresses that the signs for antialignment are small, though potentially significant. If scientists detect more antialigned systems, such evidence may support a formation scenario known as dynamical capture, in which black holes evolve separately in a cosmic environment cluttered with stellar objects. In such an environment, black holes with various spins can eventually pair up in binary systems, simply through gravitational, “dynamic” attraction.</p>
<p>Dynamical capture runs counter to a model called “common envelope evolution,” in which binary black holes evolve together, with spins that are aligned with their orbital angular momentum. In fact, the LIGO team inferred that the December 2015 detection had a strong probability of aligned spins, contrary to this newest signal.</p>
<p>“Here for the first time, we’re seeing antialignment is favored,” Katsavounidis says. “If we can detect more systems, we can nail down under what circumstances black holes formed and evolved to form binary systems that ultimately merged.”</p>
<p><strong>Real-time serendipity</strong></p>
<p>After undergoing tune-ups to improve its sensitivity, LIGO began its second observing run on Nov. 30, 2016. Katsavounidis says GW170104’s detection had “a certain aspect of serendipity.”</p>
<p>On Jan. 4, 2017, at 10:11:58.6 UTC, a gravitational ripple was recorded passing through one of LIGO’s detectors, in Hanford, Washington. Three milliseconds later it passed through the twin detector more than 3,000 kilometers away in Livingston, Louisiana. The ripple caused each detector to alternately expand and shrink ever so slightly, generating a small wiggle in the data gathered by both detectors.</p>
<p>Within tens of seconds, LIGO’s search algorithms automatically analyzed the signal, comparing it to waveforms characteristic of gravitational waves.</p>
<p>“A very careful researcher in Germany was looking at the data as they were coming in, and noticed one of the two detectors picked up something significant,” Katsavounidis says. “That event was identified in near-real time, thanks to that colleague.”</p>
<p>The researcher immediately notified LIGO’s detector operations, characterization, and data analysis working groups, which set to work further dissecting the signal. The scientists used computational tools to narrow in on a likely set of parameters, such as a system’s mass, spin, and orientation, that would produce a gravitational signal matching the one seen in the data.</p>
<p>The best fit turned out to be a pair of merging black holes, which the scientists calculated to be the second most massive stellar-mass binary black hole system, behind GW150914, LIGO’s first gravitational wave detection.</p>
<p><strong>Fighting gravitational fuzziness</strong></p>
<p>With this new detection, the team again confirmed Albert Einstein’s theory of general relativity, observing that the behavior of the merging black holes agreed with Einstein’s predictions of gravitational effects, even at such extreme scales.</p>
<p>“That’s an amazing thing,” Katsavounidis says. “Whether you talk about gravity on Earth, or something where the gravitational potential is a billion times greater, general relativity still describes how those gravitational waves are generated and how those objects behave gravitationally.”</p>
<p>As part of the initial analysis of the signal, LIGO researchers produced “sky maps” with approximate areas in the sky for where the binary black hole system might be located. As part of its standard procedure, LIGO sent these sky maps out to about 80 partner astronomy groups, each of which has access to imaging tools that span the entire electromagnetic spectrum, as well as neutrinos. While LIGO continues to listen for signs of other extreme events in the universe, astronomers have been pointing their telescopes in the direction of GW170104’s source, hoping to see glimmers of the colliding black holes.</p>
<p>“LIGO acts as our ears, so to speak, and we want to listen for something and quickly move our eyes to follow the signal,” Katsavounidis says. “Our mission is to fight the fuzziness of gravitational wave detectors by adding more of them in the global network, and by pairing [the detections] with light as soon as possible.”</p>
<p>The search for gravitational waves will soon gain an additional set of ears, in the form of Virgo, a similar detector located near Pisa, Italy, that is scheduled to come online this summer and will pair with LIGO.</p>
<p>“Coming from a field of looking for something rare, I’ve always been hesitant, with one detection only, to declare victory,” Katsavounidis says. “I can tell you I’ve started sleeping much better after the second detection. Now this third one solidifies LIGO and LIGO’s observations as the ultimate tool to see the mass spectrum of black holes in our universe.”</p>
<p>This research was supported, in part, by the National Science Foundation.</p>
This artist's conception shows two merging black holes similar to those detected by LIGO. The black holes are spinning in a nonaligned fashion, which means they have different orientations relative to the overall orbital motion of the pair. LIGO found hints that at least one black hole in the system called GW170104 was nonaligned with its orbital motion before it merged with its partner.Image: LIGO/Caltech/MIT/Sonoma State (Aurore Simonnet)Astronomy, Astrophysics, Black holes, Kavli Institute, LIGO, Research, School of Science, Space, astronomy and planetary science, National Science Foundation (NSF), PhysicsProject Apophishttps://news.mit.edu/2017/mit-students-ready-spacecraft-to-study-asteroid-apophis-0601
Space Systems Engineering students design a close-range mission to a giant asteroid that will fly by Earth in 2029.Wed, 31 May 2017 23:59:59 -0400Meg Murphy | School of Engineeringhttps://news.mit.edu/2017/mit-students-ready-spacecraft-to-study-asteroid-apophis-0601<p>Alissa Michelle Earle is rehearsing in front of her class. She stands before a presentation slide, and reads: “Mission Motivation: Apophis is coming!” &nbsp;</p>
<p>“It’s not going to impact Earth but it’s going to come very close to us,” explains Earle, a graduate student in the Department of Earth, Atmospheric and Planetary Sciences.</p>
<p>Apophis is&nbsp;an asteroid the size of an aircraft carrier that will come within 5.5 Earth radii in 2029. As part of 16.83 (Space Systems Engineering), Earle is one of&nbsp;20 students tasked with designing a space mission to measure the asteroid's&nbsp;internal structure and potential long-term impact hazard.<strong> </strong></p>
<p>Professor of planetary sciences Richard Binzel is leading 16.83 with David Miller, the Jerome C. Hunsaker Professor of Aeronautics and Astronautics,&nbsp;who recently returned to MIT after serving as chief technologist for NASA. Inspired by Apophis, the professors teamed up to issue MIT students a challenge: Build a major science robotics mission that marries planetary defense with scientific learning.</p>
<p>The ingenuity of their MIT students soon blew Binzel and Miller away. Early on, the pair advised NASA colleagues of the project and invited their participation in a series of design reviews. As Miller notes, “Both Rick and I have a rolodex at NASA, and as the class progressed, the audience for our reviews grew bigger and bigger.”</p>
<p>Today Binzel and Miller are helping students get ready for a major final review, which will be attended by NASA Headquarters officials and engineers from NASA’s Jet Propulsion Laboratory (JPL). During the trial run, the students are well-prepared but nervous — fidgeting, speed talking, making edits. As Earle speaks, a woman in the audience of students and visiting faculty shouts: “There are a lot of scientific terms you’re using here that we’ve never heard before!”</p>
<p>“You don’t need to get into the specifics right at the beginning,” coaches Binzel, who is one of the world’s top scientists in the study of asteroids and Pluto.</p>
<p>When MIT senior Diego Mundo, an aeronautical and astronautical engineering major, dives into spacecraft instrument design, Binzel interrupts: “Are you sure that will work?”</p>
<p>“I am sure,” says Mundo, who&nbsp;is dressed in a black t-shirt with&nbsp;colored bracelets covering his arms and&nbsp;hair flying out of a ponytail in all directions. But his expression is that of a stern academic as he allows that: “I may not have used the correct words.”</p>
<p>“That’s what today is for,” says Binzel. “You’re getting the feedback to make sure that everything is clear. Let’s go again.”</p>
<p><strong>Space mission</strong></p>
<p>The students want to get their performance and the science just right, since&nbsp;asteroid flyby events&nbsp;on the order of&nbsp;Apophis happen only once about every 1,000 years.</p>
<p>The students' general mission objectives include characterizing the asteroid’s shape, size, density, surface topography, surface composition, rotation rate, and spin state. A NASA spacecraft would have to be launched in August of 2026 to reach the observation position in time. The objective is to get the craft close&nbsp;enough to Apophis&nbsp;to conduct measurements before, during, and after the 2029 event.</p>
<p>Surprisingly, the student-designed mission is the first significant attempt to take on Apophis, which is 350 meters across with a mass of 20 million metric tons. At NASA, Miller says people tend to split into a couple of camps: those in space flight (or the “space cadets,” like him) and the scientists (like Binzel, whom he refers to as an&nbsp;“asteroid hunter extraordinaire”).</p>
<p>Exploration of the hazards posed by asteroids does not quite fit into either camp, Miller&nbsp;says,&nbsp;“so that kind of falls between the cracks at NASA.”</p>
<p>Project Apophis, as Binzel likes to say, is a “kick-starter” —&nbsp;designed to encourage further studies by international space agencies. And for good reason, Miller adds.</p>
<p>“There have been plenty of missions to comets and asteroids, so why is this unique?” he explains. “Apophis is coming so close that Earth’s gravity is going to tug and redirect its path. The Earth is going to give it a big thunk.”</p>
<p>The outcome of that planetary&nbsp;torque will teach scientists more about the construction of asteroids, which were some of the early building blocks of our own solar system. New information could lead to a deeper understanding of the formation of our solar system&nbsp;and the more than 4,000 known planets around other stars. More pragmatically, what we learn from the Apophis encounter could strengthen our knowledge of&nbsp;how to mount a planetary defense in the event an asteroid was ever discovered and verified to be on an impact course.</p>
<p><strong>The big day</strong></p>
<p>On the big day, the room is quiet, and the students are dressed up. Even Mundo appears&nbsp;in a&nbsp;button-up (albeit wrinkled) shirt, with his hair in a tidy bun.</p>
<p>Among the listening experts are NASA Planetary Defense Officer&nbsp;Lindley Johnson, who directs a program for detecting and tracking near-Earth objects; Paul Chodas, who heads the Center for Near-Earth Objects at JPL;&nbsp;and Farah Alibay PhD '14 a JPL systems engineer.</p>
<p>The practice sessions pay off. The students hit a rhythm, and take tough questions as smaller subteams, based on areas of expertise.</p>
<p>“How well do you know the orbit of Apophis after the flyby event?” “Do you have the equipment to change your operation plans if there’s a change in the asteroid?” “Do you know what the rotation vector of the asteroid is?"</p>
<p>The teams don't necessarily have&nbsp;all the answers: “Okay, we can look into that.” “We’ll do the analysis.” “Thanks for the input.”</p>
<p>But the experts are impressed.&nbsp;“It’s a really good effort,”&nbsp;NASA's Johnson says in an encouraging tone. “It’s almost ready for a NASA proposal.”</p>
Space Systems Engineering students (left to right) Jeremy Stroming, Tori Wuthrich, and Nicholas James compare the properties of stony and iron meteorites.Photo: Lillie Paquette/School of EngineeringAeronautical and astronautical engineering, School of Engineering, Astrophysics, Asteroids, NASA, Planetary science, Undergraduate, Astronomy, Space, astronomy and planetary science, Classes and programs, EAPS, School of ScienceUnderstanding anthropogenic effects on space weatherhttps://news.mit.edu/2017/anthropogenic-effects-of-space-weather-0531
New research from MIT Haystack Observatory reviews the ways in which human activity affects space weather around Earth. Wed, 31 May 2017 18:10:01 -0400Haystack Observatoryhttps://news.mit.edu/2017/anthropogenic-effects-of-space-weather-0531<p>Effects of human behavior are not limited to Earth's climate or atmosphere; they are also seen in the natural space weather surrounding our planet. "Space weather" in this context includes conditions in the space surrounding Earth, including the magnetosphere, ionosphere, and thermosphere.</p>
<p>A recent survey by a team of scientists including Phil Erickson, assistant director of MIT Haystack Observatory, has resulted in an <a href="https://link.springer.com/article/10.1007/s11214-017-0357-5" target="_blank">article</a> in the journal <em>Space Science Reviews</em>. The study provides a comprehensive review of anthropogenic, or human-caused, space weather impacts, including some recent findings using NASA's <a href="https://www.nasa.gov/van-allen-probes" target="_blank">Van Allen Probes</a> twin spacecraft.</p>
<p>As space scientist James Van Allen discovered in the 1950s and 1960s, two radiation belts surround Earth with a slot&nbsp;between them. The inner edge of the outer Van Allen radiation belt is particularly interesting, as it is composed of high-energy "killer" electrons that have the potential to permanently damage spacecraft. Tracking the inner edge of the radiation belt is important for GPS navigation, communication, and other satellite-based systems to help protect them from this naturally occurring radiation.&nbsp;</p>
<p>Until recently, it was thought that the inner edge of the outer belt was under nearly all conditions located at the plasmapause, the outer boundary of cold, dense plasma surrounding Earth that is produced daily by the sun's extreme ultraviolet rays. During geomagnetic storms, extra energy from solar flares and coronal mass ejections interact with and compress the plasmasphere. Scientists originally thought that under these conditions, the inner edge of the outer Van Allen belt would contract with the compression of the plasmasphere and move closer to Earth.</p>
<p>Research using the Van Allen Probes has discovered instead that during particularly intense geomagnetic storms, the inner edge of the outer belt does not follow suit but instead keeps its distance from the Earth, holding off the inner extent of "killer electrons" possessing damage potential. This inner limit to high-energy electrons occurs at the edge of strong human-origin radio transmissions created for a very different purpose.</p>
<div class="cms-placeholder-content-video"></div>
<p>Strong very low frequency (VLF) radio waves have been used for nearly a century to communicate with submarines, as they penetrate seawater well. But in addition to traveling through the ocean, the VLF waves also propagate upward along magnetic field lines and form a "bubble" of VLF transmissions, reaching to about the same spot that the ultra-relativistic electrons seem to stop during superstorms. The communications signals can interact with and remove some of these high-energy particles through loss to our atmosphere. This new understanding implies that human-origin systems can have an unexpected effect on high-energy space weather around our planet during these unusual, intense storms in space.</p>
<p>The <em>Space Science Reviews</em> survey also explores a more direct effect caused by humans on the near-Earth space environment. High-altitude nuclear detonation tests during the Cold War also affected the near-Earth environment by creating long-lasting artificial radiation belts that disrupted power grids and satellite transmissions. Such tests are now banned: In particular, the 1963 Partial Test Ban Treaty — signed by all nuclear powers at the time — specifically prohibits nuclear weapons testing in the atmosphere. However, a large body of information on the effects of these atmospheric tests exists, and the article examines these historical nuclear explosions to further study of anthropogenic effects on space weather.&nbsp;</p>
<p>Understanding human-origin space weather under these extreme conditions allows us to greatly enhance our knowledge of natural effects and allows essential engineering and scientific work aimed at protecting the planet's ground-based and satellite technology. “Nuclear atmospheric tests were a human-generated and extreme example of some of the space weather effects frequently caused by the sun,” says Erickson. “If we understand what happened in the somewhat controlled and definitely extreme conditions caused by one of these man-made events, and combine it with studies into longer term effects such as the VLF communications 'bubble,' we can more readily advance our knowledge and prediction of natural variations in the near-space environment.”</p>
<p>The work highlights the importance of continuing research into space weather — both naturally occurring effects and those influenced by human behavior — as an essential part of society's advance toward a more complex, spacefaring society.</p>
Artist's depiction of NASA's Van Allen Probes, with the Van Allen radiation belts rendered in false color for visibilityImage: NASAResearch, Space, astronomy and planetary science, Earth and atmospheric sciences, Haystack ObservatoryRivers on three worlds tell different taleshttps://news.mit.edu/2017/rivers-titan-landscape-resembles-mars-not-earth-0518
Study finds history of Titan’s landscape resembles that of Mars, not EarthThu, 18 May 2017 14:00:00 -0400Jennifer Chu | MIT News Officehttps://news.mit.edu/2017/rivers-titan-landscape-resembles-mars-not-earth-0518<p>The environment on Titan, Saturn’s largest moon, may seem surprisingly familiar: Clouds condense and rain down on the surface, feeding rivers that flow into oceans and lakes. Outside of Earth, Titan is the only other planetary body in the solar system with actively flowing rivers, though they’re fed by liquid methane instead of water. Long ago, Mars also hosted rivers, which scoured valleys across its now-arid surface.</p>
<p>Now MIT scientists have found that despite these similarities, the origins of topography, or surface elevations, on Mars and Titan are very different from that on Earth.</p>
<p>In a paper published today in <em>Science</em>, the researchers report that Titan, like Mars but unlike Earth, has not undergone any active plate tectonics in its recent past. The upheaval of mountains by plate tectonics deflects the paths that rivers take. The team found that this telltale signature was missing from river networks on Mars and Titan.</p>
<p>“While the processes that created Titan’s topography are still enigmatic, this rules out some of the mechanisms we’re most familiar with on Earth,” says lead author Benjamin Black, formerly an MIT graduate student and now an assistant professor at the City College of New York.</p>
<p>Instead, the authors suggest Titan’s topography may grow through processes like changes in the thickness of the moon’s icy crust, due to tides from Saturn.</p>
<p>The study also sheds some light on the evolution of the landscape on Mars, which once harbored a huge ocean and rivers of water. The MIT team provides evidence that the major features of Martian topography formed very early in the history of the planet, influencing the paths of younger river systems, even as volcanic eruptions and asteroid impacts scarred the planet’s surface.</p>
<p>“It's remarkable that there are three worlds in the solar system where flowing rivers have carved into the landscape, either presently or in the past,” says Taylor Perron, associate professor of geology in MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS). “There’s this amazing opportunity to use the landforms the rivers have created to learn how the histories of these worlds are different.”</p>
<p>Perron and Black’s co-authors include former MIT undergraduate Elizabeth Bailey and researchers from the University of California at Berkeley, the University of California at Santa Cruz, and Stanford University.</p>
<p><strong>Fuzzy flows</strong></p>
<p>Since 2004, NASA’s Cassini spacecraft has been circling Saturn and sending back to Earth stunning images of the planet’s rings and moons. Images of Titan’s surface have given scientists a first view of the moon’s river valleys, rolling sand dunes, and active weather patterns. Cassini has also made rough measurements of Titan’s topography in some locations, though these measurements are much coarser in resolution.</p>
<p>Perron and Black wondered whether they might refine their view of Titan’s topography by applying what is known about the topography on Earth and Mars, and how their rivers have evolved.</p>
<p>For instance, on Earth, the process of plate tectonics has continuously reshaped the landscape, pushing mountain ranges up between colliding continental plates, and opening ocean basins as landmasses slowly pull apart. Rivers, therefore, are constantly adapting to changes in topography, sidestepping around growing mountain ranges to reach the ocean.</p>
<p>Mars, on the other hand, is thought to have been shaped mostly during the period of primordial accretion and the so-called Late Heavy Bombardment, when asteroids carved out massive impact basins and pushed up huge volcanoes.</p>
<p>Scientists now have well-resolved maps of river networks and topography on both Earth and Mars, along with a growing understanding of their respective histories. Perron and Black used this foundation to gain insight into Titan’s topographic history.</p>
<p>“We know something about rivers, and something about topography, and we expect that rivers are interacting with topography as it evolves,” Black says. “Our goal was to use those pieces to crack the code of what formed the topography in the first place.”</p>
<p><strong>Conforming with topography</strong></p>
<p>The team first compiled a map of river networks for Earth, Mars, and Titan. Such maps were previously made by others for Earth and Mars; Black generated a river map for Titan using images taken by Cassini. For all three maps, the researchers marked the direction each river appeared to flow.</p>
<p>They then compared topographic maps for all three planetary bodies, at varying degrees of resolution. Maps of Earth are sharp in detail, as are those for Mars, showing mountain peaks and impact basins in high relief. By contrast, due to Titan’s thick, hazy atmosphere, the global map of Titan’s topography is extremely fuzzy, showing only the broadest features.</p>
<p>In order to make direct comparisons between topographies, the researchers dialed down the resolution of maps for Earth and Mars, to match the resolution available for Titan. They then superimposed maps of each planetary body’s river networks, onto their respective topographies, and marked every river that appeared to flow downhill.</p>
<p>Of course, rivers only flow downhill. But the team observed that rivers might appear to flow uphill, simply because a map at low resolution may not capture finer details such as mountain ranges which would divert a river’s flow.</p>
<p>When the researchers tallied the percentage of rivers on Titan that appeared to flow downhill, the number more closely matched with Mars. They also compared what they called “topographic conformity” — the degree of divergence between a topography’s slope and the direction of a river’s flow. Here too, they found that Titan resembled Mars over Earth.</p>
<p>“One prediction we can make is that, when we eventually get more refined topographic maps of Titan, we will see topography that looks more like Mars than Earth,” Perron says. “Titan might have broad-scale highs and lows, which might have formed some time ago, and the rivers have been eroding into that topography ever since, as opposed to having new mountain ranges popping up all the time, with rivers constantly fighting against them.”</p>
<p><strong>Filling in a picture</strong></p>
<p>One last question the researchers looked to answer was how cratering due to asteroid impacts on Mars has reshaped its topography.</p>
<p>Black used a simulation that the group previously developed, to model river erosion on Mars with different impact cratering histories. He found that the pattern of river networks on Mars today limits the extent to which cratering has remodeled the surface of Mars. This suggests that the biggest impact craters formed very early in Mars’ history, and that later pummeling by asteroids mostly dented and dinged the surface.</p>
<p>As Cassini’s mission is scheduled to come to an end in September, Perron says further investigation of Titan’s surface will help to guide future missions to the distant moon.</p>
<p>“Any way of filling in the details of what Titan’s surface is like, beyond what we can see directly in the images and topography Cassini has collected, will be valuable for planning a return,” Perron says.</p>
<p>This research was funded, in part, by NASA.</p>
Left to right: River networks on Mars, Earth, and Titan. Researchers report that Titan, like Mars but unlike Earth, has not undergone any active plate tectonics in its recent past. Image: Benjamin Black/NASA/Visible Earth/JPL/Cassini RADAR team. Adapted from images from NASA Viking, NASA/Visible Earth, and NASA/JPL/Cassini RADAR teamspace, Space, astronomy and planetary science, Planetary science, Solar System, EAPS, NASA, Research, School of Science, GeologyEarth Observing–1 satellite is retired, leaving a legacy of spectacular imagery https://news.mit.edu/2017/earth-observing-1-satellite-retired-leaving-legacy-spectacular-imagery-0427
Advanced Land Imager instrument developed at MIT Lincoln Laboratory helped NASA mission exceed expectations. Thu, 27 Apr 2017 12:00:01 -0400Dorothy Ryan | Lincoln Laboratoryhttps://news.mit.edu/2017/earth-observing-1-satellite-retired-leaving-legacy-spectacular-imagery-0427<p>After more than 16 years of operation, NASA's Earth Observing-1 (EO-1) spacecraft was decommissioned on March 30. The EO-1 satellite was a component of NASA's New Millennium Program to validate new technologies that could reduce costs and improve capabilities for future space missions. Aboard EO-1 was the Advanced Land Imager (ALI) instrument developed by MIT Lincoln Laboratory as an alternative to the land-imaging sensor that was used by the Landsat Earth-observing program.</p>
<p>"From its inception, ALI was intended to demonstrate new technologies that would carry on Landsat's more than 30-year legacy of continuous land monitoring while providing substantial size, weight, power, and cost reductions," says Jeffrey Mendenhall, current leader of Lincoln Laboratory's Advanced Imager Technology Group and a member of the ALI development team. "Thirty international Earth science teams evaluated a variety of ALI data — for example, data for agriculture, forestry, urban development, climate, volcanology, glaciology, geology, water management — collected over the first year of operation to assess the instrument's performance relative to Landsat program expectations. The ultimate conclusion was that ALI met, or in many instances, exceeded the Landsat 7 instrument's performance."</p>
<p>ALI not only achieved higher image resolution and quality, it also exhibited greater sensitivity and dynamic range, and realized higher radiometric accuracy. Moreover, compared to the Landsat imager, ALI was only about three-quarters as heavy, occupied two-thirds as much space, consumed one-fifth as much power, and cost significantly less to build.</p>
<p>The EO-1 satellite was launched on November 21, 2000 from Vandenberg Air Force Base in California on a planned one-year mission to collect 2,000 images of Earth. The spacecraft was designed to operate for another year and carried fuel adequate for another five years. However, EO-1 proved to be a workhorse. NASA, in collaboration with the U.S. Geological Survey, National Reconnaissance Office, Naval Research Laboratory, and the National Oceanic and Atmospheric Administration, operated EO-1 for more than 15 years beyond its intended mission life.</p>
<p>ALI has collected more than 90,000 images, many of which were groundbreaking, such as the first mapping of a lava flow from space and the first tracking of regrowth of an Amazon forest as seen from space. During its lifetime, ALI captured many dramatic scenes — depictions of the ash deposits left by the 2001 World Trade Center attacks, flooding caused by Hurricane Katrina in 2005, and the December 2015 eruption of Momotombo volcano in Nicaragua, to name a few.</p>
<p><strong>Lincoln Laboratory's role</strong></p>
<p>Lincoln Laboratory's involvement in the EO-1 mission began in January 1994. NASA asked the laboratory to conduct a study to investigate the rapid development of an inexpensive land-imaging mission that could fill the gap in data collection created when the Landsat 6 spacecraft failed to launch. The recommendations of this investigation were not implemented immediately, but the study's findings did inform the later EO-1 sensor design and mission concept. In spring 1994, Lincoln Laboratory began work with NASA's Goddard Space Flight Center to conceive a follow-on to the Landsat Earth-imaging mission. Further collaboration in 1995 with the New Millennium Program and SSG, Inc. led to the design for ALI.</p>
<p>The ALI development was a rigorous, time-intensive program of development, fabrication, system calibration, and preflight testing. "A most significant Lincoln Lab effort was the optomechanical redesign of the telescope structure using three pieces of Invar. The initial intent of an outside vendor was to use an all-silicon carbide design that we found could not be implemented. In a very short period, so as not to compromise a very demanding schedule, Vin Cerrati and Keith Doyle of the [then] Optical Systems Engineering Group redesigned and analyzed the structure to efficiently support the optics and focal plane," recalls Steven Forman of the laboratory's Engineering Division, which provided fabrication support to the lead R&amp;D team from the Aerospace Division.</p>
<p>Lincoln Laboratory delivered ALI to NASA in 1999, and the system was integrated on the EO-1 satellite at Swales Aerospace. Five days after EO-1's 2000 launch, ALI captured its first images of land. Those images showed remarkable detail of Sutton, Alaska, a small town wedged in a dark valley. Later that day, Nov. 25, ALI collected imagery of east Antarctica, the Marshallese island of Roi-Namur, and north-central Australia.</p>
<p><strong>ALI's impact</strong></p>
<p>One of the objectives of the ALI demonstration was to evaluate its imagery against that of the Landsat 7 instrument. Thus, EO-1 was maneuvered into orbit to trail Landsat 7 by one minute as it completed 14 orbits each day and repeated the collections every 16 days. Comparison of the ALI and Landsat performances on imaging the same regions at virtually the same times confirmed that the new imager could image Earth at the same level of detail (30 meters per pixel) as the Landsat sensor; however, ALI's set of sensors enabled sharper, photo-like images once the data were processed at the ground station.</p>
<p>ALI's combination of design choices resulted in an innovative system. "The Advanced Land Imager employed a new architecture that eliminated the Landsat scan mirror and implemented new technologies, such as large, modular focal plane arrays and wide-field-of-view optics," says William Brown, head of the Aerospace Division at the time of ALI's development.</p>
<p>To reduce the optical diameter of the sensor, and thus its weight, the laboratory's researchers increased the number of detectors in the focal plane array. This choice allowed a "push-broom" approach to scanning a wide swath of Earth each day. The Landsat system had employed a sensor that collected data in a "whisk broom" mode, i.e., using a single camera that focuses on narrow section of a scene. Such a whisk broom sensor is heavy and expensive, requiring large moving parts that are difficult to stabilize. "By building a focal plane that could be used as a 'push broom' to collect the data as the satellite flies along the ground track, the ALI team demonstrated that the necessary data could be acquired with an instrument that had no moving parts This was a groundbreaking technology advance," says Grant Stokes, head of the laboratory's Space Systems and Technology Division.</p>
<p>In addition, ALI used detectors fabricated from different materials to enable the use of several spectral bands for comprehensive imaging of objects and topography, and the ground data system was automated to permit one operator to quickly acquire and process ALI data. &nbsp;</p>
<p>"The lab's unique understanding of sensor technology and the mission needs enabled a revolutionary technology to be developed for the Landsat program. EO-1 demonstrated technology on orbit that was transferred to industry to enable Landsat 8," Stokes says. The Landsat&nbsp;8 instrument, the Operational Land Imager, is based on the ALI design and has been in orbit since 2013, collecting valuable data about Earth's surfaces in the visible, near-infrared, and short-wave infrared bands.</p>
<p><strong>Farewell</strong></p>
<p>When, on March 30, EO-1's operation ended, NASA had shut down the satellite by depleting its fuel, stopping all moving parts, discharging the battery, and turning off the transmitter. EO-1's orbit will slowly degrade and, in approximately 39 years, EO-1 will reenter Earth's atmosphere, where it is expected to fragment and then burn up.</p>
<p>EO-1 has had a great run. It changed the way spectral measurements are made and used by the scientific community, according to Betsy Middleton, EO-1's project scientist at NASA's Goddard Space Flight Center. EO-1 has also validated new concepts and systems for science missions, and has offered us intriguing, spectacular views of Earth.</p>
This panchromatic-sharpened, natural-color image of Boston was generated from data collected during an April 23, 2001 scan by the Earth-Observing-1's Advanced Land Imager.Image: NASASatellites, Earth and atmospheric sciences, Environment, Imaging, Lincoln Laboratory, Space, astronomy and planetary science, NASAAnother potentially habitable extrasolar planet discoveredhttps://news.mit.edu/2017/another-new-potentially-habitable-planet-discovered-0421
Some 40 light-years away, &quot;super-Earth&quot; identified as new target for atmospheric study.Fri, 21 Apr 2017 13:10:01 -0400Helen Hill | EAPShttps://news.mit.edu/2017/another-new-potentially-habitable-planet-discovered-0421<p>Once upon a time, not so very long ago, scientists could only postulate at the existence of planets orbiting other suns. Today, the race is on to find the first with signs of life, and it's hot.</p>
<p>With so many planets out there, the observational exoplanetary-science community is fiercely focused on identifying the most promising candidates for the next phase of their search, for the select few that will be first in line to command time on advanced new spaceborne and larger ground-based telescopes, scheduled to come online in the next few years. Scientists hope by observing the atmospheres of these planets they will be able to detect biochemical signatures of life.</p>
<p>Now, <a href="https://www.nature.com/nature/journal/v544/n7650/full/nature22055.html" target="_blank">as reported</a> in the April 20 issue of&nbsp;<em>Nature</em>, a new, "super Earth" candidate orbiting in the habitable zone of a nearby small star has been identified. This latest planet joins&nbsp;<a href="https://en.wikipedia.org/wiki/Proxima_Centauri_b" target="_blank">Proxima Centauri b</a>&nbsp;and the&nbsp;<a href="https://eapsweb.mit.edu/news/2017/lucky-seven" target="_blank">TRAPPIST planetary candidates reported in February</a>, at the top of the list of most promising potentially habitable planets scientists have so far identified. &nbsp;</p>
<p>The paper was authored by MIT postdocs Jason Dittmann and Elizabeth Newton, along with a team of other American and European collaborators. Dittmann, a lead author of the study who is currently working with postdoc Sarah Ballard at the MIT Kavli Institute for Astrophysics and Space Research, will be joining the group of MIT Professor Sara Seager in July as the inaugural Heising-Simons Pegasi B Fellow.</p>
<p>Located just 40 light-years away, the planet was found using the transit method, in which a star dims as a planet crosses in front of it as seen from Earth. By measuring how much light this planet blocks, the team determined that it is about 11,000 miles in diameter, or about 40 percent larger than Earth. The researchers have also weighed the planet and found it to be 6.6 times the mass of Earth, indicating it is dense and likely has a rocky composition.</p>
<p>The planet orbits a tiny, faint star known as LHS 1140, which is only one-fifth the size of the sun. Since the star is so dim and cool, its habitable zone (the distance at which a planet might be warm enough to hold liquid water) is very close. This planet, designated LHS 1140 b, orbits its star every 25 days. At that distance, it receives about half as much sunlight from its star as Earth.</p>
<p>What makes planets that transit their host stars, like this latest discovery and the other candidates before it, special is that they can be examined for the presence of an atmosphere. As each planet moves in front of its star, the star’s light is filtered through any atmosphere, the gases present modifying the spectrum. Scientists on Earth, soon to be armed with next-generation telescopes like the James Webb Space Telescope (scheduled for launch in 2018), and the ground-based Giant Magellan Telescope (currently under construction), are working to be able to tease out these subtle signals for evidence of biosignatures — chemicals that would suggest an alien planet is playing host to life.</p>
<p>As a lead author on the study, Jason Dittmann analyzed light curve and radial-velocity data and wrote the manuscript. Meanwhile, Elisabeth Newton determined the rotational period of the star. Both did their work as members of the MEarth research team at the Harvard-Smithsonian Center for Astrophysics before joining MIT.</p>
<p>When Dittmann’s Pegasi-B Fellowship officially begins on July 1, he will join the group of Class of 1941 Professor of Planetary Sciences Sara Seager. Seager’s group is focused on the search for other Earths via space mission concepts and observations, modeling, and/or interpretation of exoplanet atmospheres, interiors, and biosignatures.</p>
<p>“All planets close to Earth mass or Earth size and anywhere near their star’s habitable zone (however ill-defined) are worth pursuing in the search for life on other worlds,” says Seager, who has appointments in the departments of Earth, Atmospheric and Planetary Sciences (EAPS) and&nbsp;Physics. Seager is also a co-investigator on the MIT-led Transiting Exoplanet Survey Satellite, a space telescope within NASA's Explorers program designed to search for exoplanets using the transit method that’s planned for launch in March 2018.</p>
<p>“I am delighted that the Heising-Simons Foundation chose MIT to host one of its four inaugural fellowships. Jason brings extensive expertise in exoplanet discovery that will be a huge asset to the MIT TESS team," Seager says.&nbsp;</p>
An artist’s impression of the newly-discovered rocky exoplanet, LHS 1140b, located in the liquid water habitable zone surrounding its host star, a small, faint red star named LHS 1140. The planet weighs about 6.6 times the mass of Earth and is shown passing in front of LHS 1140. Depicted in blue is the atmosphere the planet may have retained. Image: M. Weiss/CfAResearch, Exoplanets, Space, astronomy and planetary science, Kavli Institute, EAPS, Physics, School of ScienceSeeing black holes and beyondhttps://news.mit.edu/2017/seeing-black-holes-and-beyond-ALMA-0404
Through an international effort led by MIT Haystack Observatory, the ALMA array in Chile has joined a global network of radio telescopes.Tue, 04 Apr 2017 13:50:01 -0400Haystack Observatoryhttps://news.mit.edu/2017/seeing-black-holes-and-beyond-ALMA-0404<p>A powerful new array of radio telescopes is being deployed for the first time this week, as the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile joins a global network of antennas poised to make some of the highest resolution images that astronomers have ever obtained. The improved level of detail is equivalent to being able to count the stitches on a baseball from 8,000 miles away.</p>
<p>Scientists at MIT and other institutions are using a method called VLBI (Very Long Baseline Interferometry) to link a group of radio telescopes spread across the globe into what is, in effect, a telescope the size of our planet. Although the technique of VLBI is not new, scientists have just recently begun extending it to millimeter wavelengths to achieve a further boost in resolving power. And now, the addition of ALMA to global VLBI arrays is providing an unprecedented leap in VLBI capabilities.</p>
<p>The inclusion of ALMA was recently made possible through the ALMA Phasing Project (APP), an international effort led by the MIT Haystack Observatory in Westford, Massachusetts, and principal investigator Sheperd Doeleman, now at the Harvard–Smithsonian Center for Astrophysics.</p>
<p>Before this project, the ALMA dishes worked with each other to make observations as a single array; now, the APP has achieved the synchronizing, or “phasing,” of up to 61 ALMA antennas to function as a single, highly sensitive radio antenna — the most antennas ever phased together. To achieve this, the APP team developed custom software and installed several new hardware components at ALMA, including a hydrogen maser (a type of ultraprecise atomic clock), a set of very-high-speed data reformatters, and a fiber optic system for transporting an 8 gigabyte-per-second data stream to four ultrafast data recorders (the Haystack-designed Mark6). The culmination of these efforts is an order-of-magnitude increase in the sensitivity of the world’s millimeter VLBI networks, and a dramatic boost in their ability to create detailed images of sources that previously appeared as mere points of light.</p>
<p>“A great many people have worked very hard over the past several years to make this dream a reality,” says Geoff Crew, software lead for the APP. “ALMA VLBI is truly going to be transformative for our science.” &nbsp;</p>
<p>One of the goals of these new technological innovations is to image a black hole. This month, two international organizations are making observations that will allow scientists to construct such an image for the very first time. And the portrait they’re attempting to capture is close to home: Sagittarius A* (Sgr A*), the supermassive black hole at the center of the Milky Way.</p>
<p>So much data will be collected during the two observation periods that it's faster to fly them to Haystack than it would be to transmit them electronically. Petabytes of data will be flown from telescopes around the world to Haystack for correlation and processing before images of the black hole can be created. Correlation, which registers the data from all participating telescopes to account for the different arrival times of the radio waves at each site, is done using a specialized bank of powerful computers. MIT Haystack is one of the few radio science facilities worldwide with the necessary technology and expertise to correlate this amount of data. Additional correlation for these sessions is being done at the Max Planck Institute for Radio Astronomy in Bonn, Germany.</p>
<p>Two observing sessions are taking place. The <a href="http://www3.mpifr-bonn.mpg.de/div/vlbi/globalmm/">GMVA</a> (Global mm-VLBI Array) session will observe a variety of sources at a wavelength of 3 millimeters, including Sgr A* and other active galactic nuclei, and the <a href="http://eventhorizontelescope.org">EHT</a> (Event Horizon Telescope) session will observe Sgr A* as well as the supermassive black hole at the center of a nearby galaxy, M87, at a wavelength of 1.3 millimeters. The EHT team includes researchers from MIT's Haystack Observatory and MIT Computer Science and Artificial Intelligence Laboratory (CSAIL), working with the Harvard-Smithsonian Center for Astrophysics and many other organizations.</p>
<p>“Several factors make 1.3 mm the ideal observing wavelength for Sgr A*,” according to APP Project Scientist Vincent Fish. “At longer observing wavelengths, the source would be blurred by free electrons between us and the galactic center, and we wouldn’t have enough resolution to see the predicted black hole shadow. &nbsp;At shorter wavelengths, the Earth’s atmosphere absorbs most of the signal.”</p>
<p>The current observations are the first in a series of groundbreaking studies in VLBI and radio interferometry that will enable dramatic new scientific discoveries. Data from the newly phased ALMA array will also allow better imaging of other distant radio sources via improved data sampling, increased angular resolution, and eventually spectral-line VLBI — observations of emissions from specific elements and molecules.</p>
<p>“Phasing ALMA has opened whole new possibilities for ultra high-resolution science that will go far beyond the study of black holes,” says Lynn Matthews, commissioning scientist for the APP. “For example, we expect to be able to make movies of the gas motions around stars that are still in the process of forming and map the outflows that occur from dying stars, both at a level of detail that has never been possible before.” &nbsp;</p>
<p>The black hole images from the data gathered this month will take months to prepare; researchers expect to publish the first results in 2018.</p>
<p>The MIT Haystack Observatory team of scientists includes Geoff Crew, Vincent Fish, Michael Hecht, Lynn Matthews, Colin Lonsdale, and Sheperd Doeleman (now at the Harvard-Smithsonian Center for Astrophysics).</p>
<p>The organizations of the APP are:<a href="http://www.haystack.mit.edu"> MIT Haystack Observatory</a> (lead organization), <a href="https://www.cfa.harvard.edu">Harvard–Smithsonian Center for Astrophysics</a>, Joint ALMA Observatory (Chile), National Radio Astronomy Observatory (NRAO), Max Planck Institute for Radio Astronomy (Germany), University of Concepción (Chile), Academia Sinica Institute of Astronomy and Astrophysics (ASIAA; Taiwan), National Astronomical Observatory of Japan (NAOJ), and Onsala Observatory (Sweden).</p>
<p>ALMA, an international astronomy facility, is a partnership of ESO, the U.S. National Science Foundation (NSF), and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its member states, by NSF in cooperation with the National Research Council (NRC) of Canada and the National Science Council (NSC) of Taiwan, and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).</p>
<p>ALMA construction and operations are led by ESO on behalf of its member states; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning, and operation of ALMA.</p>
The ALMA telescope array in ChilePhoto: Geoff CrewResearch, Astronomy, Astrophysics, Black holes, space, Space, astronomy and planetary science, Computer Science and Artificial Intelligence Laboratory (CSAIL), Haystack ObservatoryDavid Shoemaker named spokesperson for LIGO Scientific Collaborationhttps://news.mit.edu/2017/david-shoemaker-named-ligo-scientific-collaboration-spokesperson-0329
Senior MIT research scientist to speak for international collaboration for gravitational wave detection research.Wed, 29 Mar 2017 11:45:01 -0400Julia C. Keller | School of Sciencehttps://news.mit.edu/2017/david-shoemaker-named-ligo-scientific-collaboration-spokesperson-0329<p>Effective immediately, David Shoemaker, leader of the Advanced Laser Interferometer Gravitational-Wave Observatory Project, will assume the role of spokesperson for the international LIGO Scientific Collaboration.</p>
<p>As spokesperson, Shoemaker will coordinate and speak on behalf of the gravitational wave science carried out by scientists in 15 countries in observatories located in Hanford, Washington, and Livingston, Louisiana, as well as a detector in Hannover, Germany.</p>
<p>“I’m honored and humbled to be able to speak on behalf of my colleagues and our research on gravitational wave detection,” says Shoemaker, a senior research scientist at MIT Kavli Institute for Astrophysics and Space Research, who was elected by the LSC’s council members to a two-year term.</p>
<p>“The collaborative work of more than 1,000 scientists and engineers has allowed us to pull the curtains and peek into the new window of the universe that was opened last year,” says Laura Cadonati, a professor in the School of Physics at Georgia Tech, and chair of the LSC’s Data Analysis Council, who will work closely with Shoemaker in his role.</p>
<p>Shoemaker has been working on interferometric instrumentation since the late 1970s when he worked in Professor Emeritus Rai Weiss’ lab, earning his master of science degree from MIT in 1980. After earning his PhD in physics from the University of Paris, Shoemaker returned to the Institute in 1989.</p>
<p>He became head of the MIT group working on LIGO in the early 1990s and later headed up the Advanced LIGO Project. Shoemaker was named a fellow of the American Physical Society for this work in the field.</p>
<p>"We are incredibly proud that David and other MIT scientists have played key roles in the landmark detection of gravitational waves," says Michael Sipser, dean of the School of Science and the Donner Professor of Mathematics. "Grown from Rai Weiss's original concept more than 50 years ago, the LIGO project stands out as a marvelous achievement for science."</p>
<p>“Based on his technical experience and interactive skills with people, I expect as spokesperson of the LIGO Scientific Collaboration, he will help advance both the detector sensitivity and the data analysis,” says Weiss.</p>
<p>The original LIGO Project, led by MIT and Caltech with support the National Science Foundation, established the Livingston and Hanford observatories, reached the instrument design sensitivity, and observed for an extended period. However, they did not have success in detecting gravitational waves during initial operations which ended in 2011.</p>
<p>After an overhaul of the instrumentation for Advanced LIGO, on Sept. 14, 2015, the instruments made the first direct detection of gravitational waves, just two days after scientists restarted observations.&nbsp;</p>
<p>“David’s leadership on the upgrade of the detectors was a major factor in the LIGO Laboratory’s detection of gravitational waves,” says Jacqueline N. Hewitt, director of the MIT Kavli Institute. “He has the deep technical knowledge not only to speak to future LIGO discoveries, but also to help coordinate the research of our collaborators around the globe.”</p>
<p>Three months later, the detectors picked up another signal from another black hole merger, 1.4 billion light years away.</p>
<p>“Now with confirmed observations of binary black holes, we are really eager to see what else the cosmos will deliver in the form of gravitational waves,” says Shoemaker.</p>
<p>In November of last year, scientists restarted the LIGO system after additional improvements were made to increase the observatory’s sensitivity by 10 to 25 percent. With these improvements, the detector in Livingston, Louisiana is a step closer to detecting the gravitational waves from other objects, such as the merger of two neutron stars.</p>
<p>Nergis Mavalvala, part of the MIT LIGO Laboratory team — whose research in the instrumentation development for the interferometric gravitational-wave detectors began as a graduate student at MIT— says she, too, is waiting for that next big leap forward.</p>
<p>“In the next two years, as the LIGO instruments improve, they will, and they should, be able to see more instances of objects such other binary black holes or things we haven’t, as of yet seen, such as coveted binary neutron stars,” says Mavalvala, the Curtis and Kathleen Marble Professor of Astrophysics and the associate head of the Department of Physics.</p>
<p>A neutron star-neutron star merger is thought to be the producer and distributor of heavy metals, such as precious metals, throughout the galaxy.</p>
<p>“But I imagine, there will come a moment in time in which gravitational waves will be observed, and we’ll have no clue what the source is,” Mavalvala says. “There will be something no one predicted.”</p>
<p>Shoemaker adds, “This will be a wonderful moment where we can unravel a mystery story for which the unique key is the gravitational-wave signature.”</p>
<p>Since the second Advanced LIGO detection run began late last year, three possible event candidates have been identified and shared with LSC astronomers. The analysis of these data is still ongoing, according to news shared on the LSC website.</p>
<p>“In addition to providing leadership on the development of future large-scale gravitational wave detectors, David will be a wonderful spokesperson to communicate the exciting new findings on behalf of the collaboration,” says Gabriela González, outgoing spokesperson for the LSC and professor of physics and astronomy at Louisiana State University. “In his role, he will continue to nurture the LSC’s teamwork and help further our mission of exploring the fundamental physics of gravity — and ultimately, the universe.</p>
MIT senior research scientist David Shoemaker has been elected the next spokesperson for the Laser Interferometer Gravitational-Wave Observatory (LIGO) Scientific Collaboration. Photo: Bryce VickmarkAwards, honors and fellowships, Staff, LIGO, Black holes, Physics, Space, astronomy and planetary science, Astrophysics, National Science Foundation (NSF), School of Science